Monster Falls: Hunt for the Source
by Syke37
Summary: After Dipper stumbles across a mysterious creek in the woods and, of course, falls in like an idiot- though you'll likely hear him blame a certain goat for that one- it's to his horror that he realizes exactly what the author meant in the Journal by 'change'. Even worse, the rest of the town quickly follows suit. It's up to Dipper, Mabel and a particular triangle to find a cure.
1. Chapter 1

Dipper ambled along the dusty forest path, carrying a tattered journal in one hand and holding a pen in the other, the tip of which he chewed thoughtfully. The morning sun beams filtered through the trees overhead, dappling the forest floor with golden light. A gentle breeze rustled through the leaves, pleasantly cool for a warm summer's day. Dipper drifted off the path and into the thick of trees, not paying much attention to where he was going. He studied the contents of journal #3 carefully.

A twig snapped behind him, causing Dipper to whirl around, alarmed- only to see the sleepy, perpetually munching goat: Gompers.

Dipper sighed, then looked at the animal irritably. "What, you following me out of pity or something?" he grumbled. "Grunkle Stan and Mabel just don't know when to stop, do they?"

The two had been making fun of Dipper for his 'squeaky puberty voice' again, despite the fact that it hardly cracked anymore, something Dipper had formerly been proud of. It'd been a whole four years since they first arrived in Gravity Falls, and they recently came back for another summer visit. Surprisingly the teenage years, after a shaky start, were going well for Dipper, and while he was still rather scrawny he was overall comfortable in his own skin- except when Grunkle Stan and Mabel decided to make fun of him. Rather, it wasn't so much his physical traits that they poked fun at him for, but his personality tics. He was still obsessed with uncovering mysteries, solving puzzles and, of course, Dungeons Dungeons and more Dungeons. No one else in his family shared the same intellectual perseverance, though Mabel was still all for uncovering new mysteries. Mysteries that never seemed to stop popping up. Every year he found new puzzles to entertain him over the summer, and he made additions to the journal with each one, Mabel helping eagerly. But that didn't change the fact he was still fuming over that last bout of teasing.

"They just don't understand," Dipper went on, the goat following faithfully at his heels. "They don't know what it's like being the odd one out. It's all fun and games to them, and they never bother to put themselves in my shoes to see why I love the things I do." Dipper stopped and turned to the goat. Gompers looked up at him with large eyes. Dipper sighed. "And you have no idea what I'm saying. Why do I bother…."

Gompers gave a gentle bleat, chewing contentedly. Dipper's scowl softened to a smile. "You're a good listener, Gompers. This is getting kinda depressing though."

Dipper turned back around, and realized with a start that he didn't know where he was. He smacked himself in the forehead. "Stupid..."

He surveyed the surroundings more carefully, and slowly realization dawned on him. He _had_ seen this part of the woods before...in an illustration. Quickly, he flipped through his journal, coming to a halt on two recently discovered pages that had been stuck together, preventing access until the delicate application of goat saliva proved otherwise. On one page was a drawing of the trees around the area, ones that grew in slightly odd angles and noticeable landmarks. Surrounding it were little notes scribbled hurriedly, noting the subtle variation in colour of the leaves and needles on trees due to a certain creek with magical properties flowing nearby.

Dipper continued walking forward, previous frustrations melting into pure curiosity. He kept up his pace until the sound of running water met his ears. Advancing carefully, he spotted a brook winding through the trees, burbling gently. Dipper gazed at it in awe: the way the sun reflected off the liquid surface; the clarity of the pure waters that allowed you to see the little multicoloured pebbles at the bottom; the refreshing mist coming off the surface, rejuvenating its surroundings. And possibly discolouring the area around it in some sort of evil curse cast by a witch. Resisting the urge to plunge right in and roll around, Dipper consulted the journal.

The 'Fluvius Cantatis' was its name, enticing any and all who stumble across it in the woods, inviting them for a quick dip or gentle sip. It said that the river was given magical properties by some sort of imbued artifact enchanted by an angry nymph. Along with the carefully drawn depiction was a warning: that you must NEVER touch or drink the water, unless you wanted to be...changed.

That was it.

"Changed how?" Dipper muttered. "Good? Bad? Weird?" Knowing Gravity Falls, it was most likely weird. Then again, Dipper reasoned, the author wouldn't have inserted a warning if it wasn't dangerous.

Dipper eyed the brook warily, then took out a roll of yellow police tape from his jacket. He still had some left over from the crime scene with Wax Stan. He walked along the bank, laying it out on the side nearest to the town and the Mystery Shack so that anyone who happened to stumble across it would take the hint and leave. At intervals he left rocks sitting on the tape to weigh it down, preventing it from drifting away in the breeze. Once he was sure he'd gone far enough, he took a step back and surveyed his handiwork, content.

Just then, Gompers bleated and bumped into Dipper from behind, causing him to lurch forward with a yelp of surprise. He teetered on the edge of the bank, arms flapping, before steadying himself and breathing a sigh of relief. At which point the fragile ground promptly gave out beneath him, sending him sliding down the bank and face planting straight into the river. He gasped in surprise at the freezing water, accidentally inhaling some, leaving him spluttering. He climbed out frantically, attempting to shake off the water in terror. After freaking out for a few minutes, convinced he was seeing things and that his insides were being turned out, he finally began to breathe again. After a moment he realized that nothing was happening, and he immediately felt like a moron. He shot a betrayed glare at Gompers, who continued chewing peacefully. With that, he carefully rolled up the rest of his police tape and made his way back to the Shack, slightly disturbed. Surely nothing _too_ serious could happen.

Could it?

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 **Thanks so much for reading! Any constructive criticism and suggestions are welcome.**

 **I'll be posting this on Tumblr as well, you can find me at shadysfics.**


	2. Chapter 2

Mabel carefully placed the final coffee-sweetening cream packet on her tower of creamers. With a happy exclamation she jumped up, punching the air in excitement. "Behold, Grunkle Stan! The latest work of Mabelangelo, the Leaning Tower of Cream!" She gestured at her creation. It stood three feet high off the dinner table, and was indeed slightly lopsided. Stan looked up from his newspaper, giving an affirmative grunt. That was his way of showing appreciation, Mabel was sure of it. She glanced around, noting the absence of a tousled bedhead. "Grunkle Stan, still no sign of Dipper?"

He grunted again, flipping through his newspaper leisurely. "Haven't seen the little runt since breakfast. Still fuming I s'pose."

Mabel sank down in her seat, dismayed. "He knows we were just joking, right?"

Mabel too had grown significantly over the past few years, blossoming into a lovely young woman. Her braces were a thing of the past, leaving her teeth even and perfect. Her personality hadn't changed much, she was just as bubbly and energetic as ever. High school wasn't as bad as she anticipated either, but with her senior year left to go she was still unsure of what the future held for her. Dipper too was doing well, he was as self-assured in his studies as usual, and he was a model student. He had grown to be quite tall, surpassing Mabel, and had a female following among the studious that he was completely oblivious to. Mabel, on the other hand, was promised to be team captain of the female senior basketball team this year due to her remarkable skill and athletic prowess. In terms of their clothing, Mabel's love of sweaters remained as strong as ever, though now instead of skirts she preferred leggings. She still wore her hair long and straight with a headband to keep it in place. A small purse full of essentials (such as gummy worms) usually hung from her shoulder. Dipper's outfit had changed; instead of a vest and shorts he wore a dark blue flannel shirt with a black undershirt and jeans. He typically carried a bag for his journal and other mystery-solving equipment, though his pants' pockets seemed to be a dimension of their own. He retained the classic pine tree baseball cap, and the perpetual dark circles under his eyes remained from his numerous all-nighters.

Mabel sat slumped in her chair, regretful that she upset her brother. She traced a grain of wood in the dinner table as she spoke, "didn't he say he had some kind of investigation happening in town today, though? It's almost noon already! He's been gone for over an hour. If he doesn't come back soon, he'll be late!"

Stan merely shrugged. "Look, pumpkin, he'll be back soon, all right? There's no way he'd miss...whatever it is he's doing."

As if on cue, the door to the Shack burst open, and in staggered Dipper. He was sopping wet and had needles and leaves stuck in his clothes and hair, which was a frazzled mess. Not only that, but his eyes kept darting down nervously, as if he was afraid of his own skin.

Mabel and Grunkle Stan stared at him.

"What, you lose a fight with a garden hose, kid?" Stan chuckled.

Mabel couldn't help but burst out laughing. "Dipper, what on earth happened? You're a mess!"

"I fell in a river," came the irritated reply as he removed his shoes at the door to prevent tracking mud on the carpet. He looked around before heading for the stairs. "I'm gonna take a shower," he said quickly, scratching his arms.

Mabel watched him go, bewildered. She shook her head. "And here I thought he'd gotten better at avoiding mishaps like that. Also- did he just say he's going to take a shower?! Is he possessed? Grunkle Stan, we need to investigate this!"

"Mhmm, sure. Later," Stan grunted, not moving from his recliner. Mabel sighed. This was going to be a boring day.

The ceiling fan spun above the lounge area nonchalantly. Neither Stan nor the Shack had changed over the years. The old TV still sat in its usual place, playing black and white soap operas, with Stan's favourite chair planted firmly in front of it. Oddities were scattered everywhere, and the slightly musty air filtered through the sun beams that were cast into the room. Mabel leaned back in her chair, staring at the small cracks in the ceiling plaster. She smiled contentedly. There was no place she'd rather be.

Shortly later Dipper descended the stairs, adjusting his cap and checking his watch. "Well, I'll be going now. Pacifica told me to meet her by one o'clock-"

"Oooh!" Mabel teased. "Has someone got a date with the pretty lady?"

Dipper scowled at her. "Don't be ridiculous, Mabel! She said she found something paranormal in that secret room we found when I was helping them exorcize that ghost a few years ago. Y'know, the one that has all those secrets about her family. A bunch of weird stuff keeps popping out of it that I have to deal with."

Mabel laughed. "Uh huh, that's what you always say!" She got up from her seat and patted his shoulder affectionately. "Don't worry Dipper, I can keep a secret," she said, winking.

Dipper rolled his eyes. There was no convincing her otherwise when it came to subjects like these. "Anyway, I'm off. I'll see you guys later."

With that, he left the Shack and headed down the road to town, hands in his pockets. Mabel watched him from the window, frowning. He seemed...worried. About what? She considered for a few moments, then shrugged. He'd cheer up after some investigating.

Wait a minute, Mabel realized. Aw, man! This meant she was stuck by herself with nothing to do! She was initially going to ask Dipper if she could tag along, but decided to leave him alone for his date or whatever. She eyed Grunkle Stan critically. He was settled deep into his chair, and it would take effort beyond belief to drag him out of it to do something fun. She considered her other options. Candy and Grenda were busy, and the Shack was closed for Sunday, meaning Wendy and Soos weren't around. It was up to her to conquer the crushing boredom. Alone.

She flung herself away from the window, grabbed Waddles who emitted an indignant 'oink', and reached under the table to retrieve her precious grappling hook. All set for adventure, she kicked open the door and called goodbye to Grunkle Stan before journeying into the forest.

"So...hot..." Mabel groaned. It had been a whole ten minutes of leaping around and shouting amidst the trees since she set out on her quest, and the temperature had risen significantly since then. Or maybe it was the sweater Mabel refused to take off. Either way, she was _way_ overcooked. Even Waddles, normally so optimistic and full of life (according to Mabel anyway), was drooping wearily. Mabel stamped the ground angrily. "Why does summer have to be so dang hot anyway?!"

The cheerful birdsong that permeated the air didn't exactly reflect her feelings. The earlier breeze had died down, and even the shade of the trees wasn't enough to prevent the blistering heat that had become Mabel's mortal enemy. She cast a forlorn glance at her grappling hook. The adventure would have to wait until she found some way to cool off.

Holding her head high, she strode through the trees purposefully, Waddles trundling along behind her.

After a few minutes of walking, a flash of yellow caught Mabel's eye. Curiosity piqued, she headed in its direction. The distant sound of rushing water grew in volume, until she emerged from the trees to be standing on the edge of a river bank, overlooking a creek. The cool air that drifted off the surface tickled her skin, making her sigh in relief. She walked a few paces down the length of the river until she met Gompers the goat. He was standing by the river bank, something bright yellow sticking out of his mouth as he chewed. Mabel frowned. "What's that you've got there?" She reached down to tug the item free, only for the rest of it to disappear down the animal's gullet. She sighed in frustration. "Gompers! Y'know that probably wasn't good for you, whatever it was."

She turned her attention back to the brook. The wonderfully cold-looking water flowed gracefully, the soft mist forming rainbows in sunlight that shone through the trees. She picked her way down to the water's edge before kneeling down and cupping it in her palms, bringing it to her lips gently. Refreshed, she then fluttered her hands through the clear water, marveling at the way it partially refracted the light to shine off the surface and through to dapple her hands. Mabel smiled. She had conquered her boredom with a simple discovery.

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 **Gompers, what have you done?**


	3. Chapter 3

The great oak doors to the Northwest Mansion opened with a mighty creak as Dipper stepped out into the sunlight, blinking. It'd taken a few hours, but he and Pacifica had finally located the source of the vengeful spirit that had been pestering the Northwests recently. Well, one vengeful spirit of many. Apparently, ever since Dipper and Pacifica had disturbed the secret room and gave that lumberjack spirit peace, many other _things_ living inside had become unsettled. Upon further investigation, it appeared that the Northwests had a history of treasure hunting as well, rather than only stealing from others and claiming credit. Many objects hidden in that room were tied emotionally to people that had died, and the only way to set the spirits free was to perform an exorcism ritual using the journal as a guide. They performed the ritual after locating that particular spirit's source buried beneath many boxes and other artifacts, and were now leaving the mansion for some fresh air.

Dipper looked over the town from the mansion's vantage point. The sun was well into its daily routine, meaning it was already late afternoon, and a haze of heat rose from ground. Suddenly Dipper was glad he had spent the afternoon in a cold, stuffy room rather than lying face down on the floor of the shack trying to keep cool. That was pure agony. His mood had improved as well; in all the time he'd spent focusing on his task in the manor the events of the morning had already slipped to the back of his mind.

Pacifica stepped out next to him and stretched lazily. She had grown to be about the same height as Mabel, and she cut her hair to about shoulder length, possibly in an act of rebellion against her parents. Her clothes, while still fashionable, weren't quite as formal and perfect as they were when she was twelve, and she'd toned down the make-up considerably. She'd put her own spin on her appearance rather than conforming to how her parents wanted her to appear. Life hadn't exactly been pleasant for Pacifica since she'd let the townspeople into the Northwest party four years ago in order to put the lumberjack spirit to rest. Apparently there'd been a lot of backlash from her parents over the whole thing, but she'd had enough. Since then she'd been determined to never follow in her parents' footsteps and chart out her own course for life. Her attitude had cleaned up a little, and while she still didn't completely get along with Mabel and could be somewhat snobby, she had come a long way from where she once was.

Now she smiled at Dipper. "Thanks for the help. I know it must be annoying having to come up here all the time."

Dipper shook his head. "Not at all. We make interesting discoveries every time, and I'd like to find out more about this treasure hunting stuff."

Pacifica tilted her head thoughtfully. "I could look into it, I suppose. I'm sure there are lots of records written about the Northwests stashed away in my dad's study." She grinned. "Nothing a little breaking and entering won't solve."

Dipper raised his eyebrows skeptically. "Breaking and entering in your own house? What a heinous crime."

Pacifica giggled. "The way my dad makes a fuss about it, it'd might as well be. You should see his face whenever I 'misplace' something important of his."

Dipper smiled. "So it's safe to assume you're the reason for all the gray hair on his head this year?"

She laughed. "I think it's your influence that's to blame here."

They continued talking and laughing as they left the property, heading down the winding path into town. A large group of people had gathered in the square, holding money and waving it above their heads. A small stand was situated before them, and they struggled to be at the front of the line. Whatever they were selling, it seemed everyone wanted it.

As they got closer, Dipper peered through the masses and was surprised to see Mabel running the stand, accepting money and filling paper cups with liquid from a large dispenser, handing them out to the thirsty customers.

Dipper frowned. It _was_ a hot day and all, but everyone seemed a little too...ravenous for his liking.

He rounded the pack of people, coming around the back with Pacifica following closely behind. "What the heck's going on?" she muttered, barely audible over the loud throng of people.

Mabel, in all her pink-sweatered glory, was standing in front of a wheelbarrow filled with ice. Nestled in the ice was the dispenser she was using, and from it she poured yet another cup and handed it out quickly. Standing next to her was none other than Grunkle Stan, his booming laughter easily heard over the crowd as the cash register became increasingly full.

"Mabel, Grunkle Stan? What's going on?" Dipper shouted over the noise.

"Dipper, you'll never believe it! This water is selling like hotcakes! And it's all thanks to Mabel here." He patted her shoulder affectionately as she turned to face them, smiling.

"Hey bro! How'd your investigation go?" She asked, pouring another cup.

"Uh, pretty well," Dipper said, distracted. "But-"

"Here!" She interrupted, handing him the cup and another to Pacifica. "You guys are special, so it's on the house."

"Um, thanks," Pacifica mumbled, still off-put by the girl's kindness. She took a sip gingerly.

Dipper glanced down at the water, sloshing it in the cup. He _was_ pretty thirsty after spending all afternoon cramped in a dusty room, but a question still nagged at the back of his mind. Why was plain old water selling so well? Not to mention the price; the sign said $5 a cup, no doubt Gunkle Stan's doing.

He glanced at Pacifica, who had taken to staring at her cup in wonder. "Whoa..." she breathed, before quickly gulping down the rest.

Mabel giggled. "I know right?"

Dipper resumed his staring contest with his cup, finally shrugging and taking a sip. It certainly was delicious, and oddly familiar. The incident with the magical river flashed in his mind. He went very still.

"Mabel, where did you get this from?"

"Oh, you won't _believe_ it!" Mabel said excitedly, continuing to pour cups for the needy customers. By now the crowd was dying down, everyone satisfied with their purchase and heading home. "So I decided to go on an adventure, right, and I came across this little river. It was shady as heck, but it was _so_ pretty and clear, and when I took a sip it was the best water I've ever tasted!" She giggled again. "Me, loving the taste of _water_! Who thought that could ever happen, right? But anyway, I ran back to the Shack and told Grunkle Stan about it, and we hatched this brilliant plan to sell it to all the people today! I've had to go back and refill this thing twice."

Dipper stared at her. No, it couldn't be...he'd only managed to find the river with the help of the journal, it was so far out of the way. Could Mabel have stumbled across it in pure coincidence?

"Mabel, was the river marked with yellow police tape?" he asked, suspicion growing.

Mabel frowned. "No, nothing like that there. Why?"

"Uh, no reason," Dipper muttered shakily. No police tape? So it wasn't the one? He had to be sure. He wracked his brain, mentally mapping out the area around the Shack. South of the Shack was toward town, and north was leaving Gravity Falls altogether. The woods stretched out further east and west, and the river was located in the east... "Mabel, what direction was the river from the Shack? East or west?"

But Mabel was already handing out more drinks, and Dipper's anxiety grew.

"Mabel! East or west?"

"Er, yes!"

Dipper slapped a hand to his forehead. "Mabel, that wasn't a yes or no question!"

"Um, west, I think," she said distractedly.

Dipper sighed in relief. So it wasn't the one...provided Mabel got her directions right. He looked back down at his cup. Just good tasting water... he thought. And besides, nothing has happened to me yet. That journal is at least 20 years old. If the river ever _was_ magical, it's probably fine now. Probably.

Soon the rest of the customers headed home, and most of the water had been sold. Stan helped himself to the last cup and continued counting the cash in pure glee. After waving goodbye, Pacifica headed back home as well, promising Dipper she'd get back to him on the Northwest treasure hunting business. Mabel nudged him, winking, and Dipper told her to shut up again. She also mentioned that even Pacifica's parents had come down for some of the rumoured water while he was rummaging through the mansion's secret rooms. It seems like the whole town (which wasn't very big, mind) had come for a taste, including Soos and Wendy with all her friends, as well as Grenda and Candy.

Now the three of them headed back to the Mystery Shack for dinner.

Dipper poked at his meatloaf gingerly (though Stan called it 'Stanloaf' since he presumed he'd gotten his own hair in it). For whatever reason, the thought of eating made him feel rather queasy. And no, despite all logic, it wasn't because of the Stan hair.

The Pines were gathered around the dinner table, Mabel and Grunkle talking happily about their success while Dipper mostly just sat there in silence. Even though there was no real evidence to prove that the effects of the river were indeed true, he couldn't help but feel worried about it.

"What's the matter, champ?" Stan said suddenly, startling Dipper so badly he dropped his fork.

"Oh! Uh, nothing much. I'm just...not very hungry."

Stan raised an eyebrow skeptically. "You, not hungry? A teenage boy? You'd usually eat twice this much given the chance."

Dipper's face turned slightly pink. "Well, maybe hunger isn't the issue..." More like the meat itself was the problem, but he couldn't bring himself to say it and hurt Stan's feelings. The thought of eating it made him feel sick, and Dipper couldn't figure out why.

"Eh? What was that?" Stan grumbled.

"N-nothing!" Dipper said quickly, standing up. "Well, I think I'm gonna go to bed...been a long day." After bumping into just about everything in the room, he scurried upstairs, Mabel and Grunkle watching, confused.

As he ascended the steps to his and Mabel's room, his queasiness grew. He'd broken out into a cold sweat, and his head began to swim. "Something's wrong," he murmured. The room teetered before him, shapes blurring together, then the floor rushed up to meet him and the world went black, an echoey, high-pitched laugh ringing in his ears.

When Dipper's eyes finally flickered open, he was the most uncomfortable he'd ever been in his life. The birds were chirping and sunlight was shining through the triangular window, meaning it was already morning. He was still lying on the floor on his back, twisted at an awkward angle with the biggest kink in his neck he'd ever experienced. Worse than that, every nerve in his body felt like it was on fire, and he could hardly feel his limbs. He twitched his right hand, then his left. At least those still worked. Then he attempted to sit up, only for him to flop back down after barely raising his head. Like a turtle.

Dipper gasped as the events of the previous day flooded back to him, in particular the river incident.

He wasn't turned into a turtle was he?

A splitting pain raced across his skull, and his hand flew to his head. Wincing, he rubbed the spot gingerly, and his hand brushed against something soft. After discovering it was a part of him, he felt along the appendage carefully, horror growing. It was very sensitive to the touch, and he realized it was an ear. An ear of _what_ he didn't know, but sure enough, he had two of them.

At least that was normal.

He made sure the rest of his face was okay and that he hadn't sprouted a third eye or something before attempting to sit up again. He shifted to the side and used the bed next to him to haul himself up before looking down. His breath caught in his throat. The entire lower half of his body had been replaced with that of a deer, complete with shiny black hooves, caramel spots, a white underbelly and a fluffy white tail. His legs were twisted awkwardly beneath him, which probably would've been painful if he could actually feel them.

He spent a few seconds processing the situation in his shocked brain before finally attempting to stand. Balling his fists in the covers of the bed, he began to pull himself up, forcing his numb deer legs to arrange themselves beneath him. Controlling two legs was hard enough for a slightly awkward teenager, and now he had to manage four? The new body was absolutely foreign to him, and he had significant difficulties trying to figure out which limb to move. It was similar to when he'd arrange his fingers in a disorganized knot and would look at them, try to guess which finger was which and move them accordingly.

Finally he got himself into a standing position and let go of the bed. He teetered for a moment and took a step forward. The blood had returned to his legs, letting him feel them again, and he focused on moving the correct legs in the correct order. He was finally getting the hang of it when a thought occurred to him.

Stairs.

He groaned.

Making his way to the steps carefully, he peered down the steep flight. With a frown he realized the house was completely silent, and Mabel's bed was empty. Where were they?

Planting one hoof on the uppermost step, he began the descent. The descent that soon became a narrowly controlled fall, with him skittering down the stairs, hooves sliding off the wooden steps until he landed in a heap at the bottom. Groaning, he pulled himself to his feet once again.

Out of the corner of his eye, he spotted a gray, marbley lump on the floor. He anxiously wobbled himself over to the lump and realized with a start that it was Grunkle Stan. He was wearing his usual white undershirt and striped blue pajama bottoms, as well as his purple slippers- which did something to slightly undermine his frightening appearance. His entire body was covered in granite, and two large, bat-like wings rose from his back. His hands and feet were clawed, and a thick tail trailed out on the floor behind him. His eyes were shut and his chest rose and fell with breath.

Dipper stared at him in shock for a moment, then kneeled down on his front legs, shaking Stan fiercely. "Grunkle Stan! Wake up!" The old man grumbled in his sleep and rolled over, brushing him off.

Dipper rolled his eyes. He'd be fine. Getting up, he began the search for Mabel. After stumbling around for a while, he found her in the living room, collapsed on the carpet with one arm stretched out in front of her. Replacing her legs was a long, pink, frilly mermaid tail. Something was wrong. She was twitching slightly, and the pink scales were turning a grayish colour. Dipper's sensitive ears picked up choked breathing and, all unsteadiness forgotten, he bounded over to her side immediately. He rolled her over, heart hammering in his chest. While still unconscious, her face was ashen and twisted in discomfort. Her breathing was dry and raspy, and she grasped at Dipper's shirt collar subconsciously.

Water.

Hastily, he gathered her up in his arms, clopping over to the stairs and ascending quickly. He barged into the bathroom and set Mabel down next to the tub gently. Proceeding to fill it with water, he remembered what he'd heard about fish needing coolish water to survive and that warm could harm them. But Mabel was only half fish now, so he kept it lukewarm and hoped desperately it would be enough.

Once he'd adjusted the temperature properly, he picked her up again and placed her in the tub, continuing to watch her carefully. Very slowly the colour returned to her cheeks and her scales shimmered serenely. A more relaxed expression crossed her features and Dipper breathed a sigh of relief. He didn't realize how stiff he'd gotten, sitting with his elbows on the edge of the tub, legs tangled beneath him and chin resting on his interlocked fingers. He shifted his position, mind still whirling. He _had_ to fix this somehow. Dipper closed his eyes wearily.

"HOT BELGIAN WAFFLES!"

Dipper smiled dryly. Well, at least Grunkle Stan was awake.


	4. Chapter 4

**Thanks so much for the kind reviews everyone :) It really makes the hours of writing worth it.**

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When Mabel finally woke up, she screamed.

This scream was due to many conflicting reactions at once, the first being because she'd just woken up with two faces staring down at her with rather constipated expressions. The second being when she focused on who she realized was her brother, she noticed that he had two fluffy ears sticking out from either side of his head in the most adorable fashion. Pure cuteness. When she turned her head to the left, however, her eyes met with Grunkle Stan. Grunkle Stan was scary enough on his own, but now his face was made of stone, had horns poking from his head, fangs, and glowing yellow eyes. Pure terror.

At once the two started shushing her, telling her it was just them. Which she knew, obviously. Then she looked down at her legs. At least, where her legs _used_ to be. And screamed again.

 _This_ scream was at first in shock: _ohmygoshwhathappenedwherearemylegs_ , but then quickly turned to joy: _ohmygoshwhathappenedImafreakingMERMAID!_

Finally she stopped and turned back to the two. Dipper had his hands clasped over his ears and Stan was grimacing in pain.

"What _happened_?"

They were all crammed into the bathroom, with Mabel lying in a tub of water, Grunkle and Dipper sat before it. Stan did his best to keep his wings and tail tucked in so he didn't knock anything over, but it was all rather precarious.

Dipper cleared his throat, not meeting her eyes. "Well, as you can see," he said, standing to show her, "we've all turned into monsters."

As he stood, she gasped. "You're so much more of a deer than usual! What are you called? Like a centaur, but with a deer. A deer-ta-"

"It's called a cervitaur," Dipper interrupted. "A variant of a centaur." He sighed sadly.

Mabel giggled. "Well, if it's any consolation, you're adorable."

Dipper rolled his eyes.

Mabel turned to Grunkle Stan. "And you're...a gargoyle?" He looked ridiculous, a terrifying creature in his undershirt and striped pajamas.

Grunkle Stan sighed. "Looks like it, kiddo." Now he had a body that matched his rough, gravelly voice.

Mabel clapped her hands excitedly. "I know! I'll call you my GarGrunkle!"

Dipper stifled a laugh while Stan gave her a look.

Stan nudged Dipper. "So, genius? Wanna tell us exactly what's going on?"

Dipper visibly deflated, one of his ears twitching nervously. "Well," he began, "yesterday morning when I went for a walk, I came across a river..."

He told them rather haltingly about the properties of the Fluvius Cantatis and how it 'changed' anyone that came into contact with it. Then he told them how he'd come across it.

As he recounted the tale, Mabel's eyes grew wider and wider. This was the river they'd found in the journal! And Dipper discovered it without her! At first she was a little miffed, but then she remembered that it was her and Stan's teasing that sent him on that walk in the first place, and she immediately felt bad.

When Dipper mentioned the police tape, she interrupted him. "But hold on, _I_ didn't see any police tape, and obviously we went to the same river..." she gasped." Unless there are _two_ magical rivers-"

Dipper held up a hand. "No, Mabel, there's definitely only one. Something must've happened to the police tape for whatever reason. Anyway, after I finished laying it out along the bank to keep people away, Gompers pushed me into the river."

Mabel let out a small, "oh." She looked up at them. "Gompers."

Dipper gave her a confused look, then realization dawned on him. He slapped a hand to his forehead once again. "Gompers..."

Once they finished comparing stories of their discoveries and added everything up, silence fell over them. When Mabel glanced at Dipper she could tell he blamed himself for what happened, but she felt equally responsible. She'd sold the water to the whole town, after all.

Wait. The entire town?

Mabel gasped. "Dipper! I sold that water to practically everyone in Gravity Falls!"

Dipper's eyes widened and his ears flattened to his head. "Everyone...Soos? Wendy?"

Mabel nodded, biting her lip. "Candy, Grenda..."

Dipper rose stiffly. "We have to see everyone...and provide an explanation, probably."

Grunkle Stan, who'd been quiet for the most part, stood up. "Kids, those townsfolk aren't gonna be happy. Let me take the blame."

They stared at him for a moment, then both began to argue against it at once. Stan raised his hand, halting them. "Listen rascals, it's _my_ responsibility to look after you, and look what happened. I mean, what am I gonna tell your parents? I've done a pretty crap job of being a respectable Grunkle. Let me talk to everyone."

Dipper closed his mouth and traded a worried glance with Mabel. He took a deep breath and nodded. "All right, Grunkle Stan. I'll look in my journal and see if I can find a cure. But we should also see the rest of the town and how they've been affected." He made for the door. "And...thanks."

Grunkle smiled, patting his head.

"Hey!" Mabel chirped. "What about me?"

They both stopped and turned to look at her. This was gonna be an issue.

In the next half hour they'd managed to set something up. They filled a small over ground pool (that Stan practically pulled out of nowhere) with water and placed it in the main part of the Shack, in the corner between the vending machine and the cash register. Stan carried Mabel over to it and plopped her inside. She held on the rim, head resting on her arms as she peered out at the both of them.

"This'll have to do until we find a better solution," Stan grumbled.

Mabel nodded and looked down at her tail. It was very vibrant, the scales shimmering in the water. A large frill ran down the back that she supposed would help her make quick turns when swimming, and the end widened into a large, fluttery crescent. She'd replaced her sweater with a pink swimming top that matched her tail. Mabel, as always, adapted well, and was already mostly used to the change. Now she just wanted to test it out in some deep water.

Dipper, meanwhile, was flipping through his journal frantically. He'd donned his cap once again, leaving room for his fluffy ears. "Ugh! I can't find anything about a cure! Not even the black light revealed anything." He made to pace around the room only to trip over his feet, furthering his frustration. "And this stupid body isn't helping either."

"Look, kid, at least _you're_ not made of stone," Stan grumbled.

"Well at least _you_ don't have to learn how to walk again!" Dipper cried.

Mabel rolled her eyes. "At least you _can_ walk!"

They all fell silent, looking at each other. Suddenly they burst out laughing. The whole situation was ridiculous.

"Seriously though, how did you manage to carry me up the stairs if you can barely walk?" Mabel said to Dipper.

Dipper shrugged. "I don't know, I just saw you there, and...wasn't really thinking about it."

Mabel snapped her fingers. "Aha! I know exactly what your problem is. You're over-complicating things again." As was his habit, Dipper often made things more complex than they needed to be, and it certainly seemed to be the case in this situation as well.

Dipper frowned. "Over-complicating it?"

Mabel gave an exasperated sigh. "Yes! Look, when you're walking on two legs, do you ever think about it? No! You just do it. Same thing here. Let your instincts do the thinking for you."

Dipper sighed, looking down at himself. "I suppose you're right." He started forward, closing the book and staring at the floor. He let out a breath and began to walk in wide circles. He started out unsteady with an uneven gait, but once he learned to relax and do as Mabel said, he was trotting along with ease. Grinning, he turned to Mabel. "You're right, it's actually easy. Thanks, sis."

Mabel waved a hand. "Don't mention it, bro-bro. Now that you're walking better," she said, pointing at him. "Wanna give me a ride to town?"

Dipper's eyes widened. "Don't be silly."

Mabel rolled her eyes. "What? I have to get around somehow, don't I? Plus, you're plenty big enough to handle it."

"But, what about water? Don't you need it to breathe?"

"Dipper, does it look like I'm breathing it right now? I need water so I don't dry out, but I don't need it to breathe. I'll just carry a water bottle or something."

"Just do it, kid. My tired old back can't carry anyone," Stan grumbled from his spot by the register. He was likely still getting used to the weight of his wings, rolling his shoulders and growling under his breath.

"Okay, okay," Dipper muttered.

"Sweet!" Mabel said excitedly. Using only her arms, she hauled herself out of the pool so that she sat on the rim, flowing pink tail trailing on the floor before her. Dipper positioned himself so that he was standing next to her, and helped carefully lower her onto his back so she sat side-saddle. He shuddered at the cool water and the feeling of fish scales on his fur. Mabel whooped. "Awesome! Now, onward, my steed! To town!"

"Don't call me that," Dipper grumbled.

By the time they arrived in town, the sun had already reached its highest point in the sky. Thankfully the day wasn't nearly as hot as was previous, otherwise Mabel would've burned to a crisp. Dipper walked as smoothly as he could to avoid her sliding off, but he occasionally wound up getting his stride confused again and he'd have to remind himself to just let it come naturally. Dipper looked back at her now. She was smiling, enjoying the ride and breathing in the refreshing air. In a bag she was carrying a few plastic water bottles which she occasionally took sips from. Surprisingly Dipper's back didn't hurt at all, and while his legs were still a little unsteady under the weight he realized his new body was very well-built.

Grunkle Stan strolled next to them, shielding his eyes from the sun and looking around. "Hmm, no one yet. They must still be asleep. That or having serious meltdowns." He always knew how to look on the bright side of things.

They continued walking until they reached the town square, in the middle of which stood a huge fountain honouring the founder of Gravity Falls: Nathaniel Northwest.

Dipper dropped Mabel into the fountain, who squeaked in surprise as she landed with a splash. "Dipper!"

"Ahh, that's better," he said, stretching. He twisted around, frowning at the wet matted mess Mabel had left his fur. He razzed a hand through it, making the water fly out in little droplets and leaving it standing on end before he smoothed it down.

Suddenly, one of the doors to a nearby house opened, and out staggered Wendy. She was covered head to toe in red fur, with fluffy ears sticking out from under her hat and from behind a bushy tail. She had a black nose and large canines that poked out from her mouth. Her shoes were ripped with clawed toes sticking through the ends, a similar set of claws on her hands.

Blinking in the sun, she wobbled toward the Pines. Dipper trotted over to greet her nervously. "Wha... _Dipper_?" She asked as she focused on him. "What the heck's going on?" Looking down at the rest of him, she let out a puff of laughter. "You look adorable by the way."

Dipper blushed. He was over her for the most part, but he was still embarrassed by his new form. "Uh, Wendy! So, um...oh gosh. This'll take some explaining," he muttered.

She grinned, baring her fangs. "No worries dude, this is totally rad! Look at these teeth! My whole family ended up like this."

Wendy had graduated from high school (which she said was a total relief) and was now working full time at the Mystery Shack. She'd also taken an interest in lumberjack work and helped her dad out occasionally at his mill.

For now, though, she seemed to be enjoying her new appearance. "I think we got turned into werewolves? I dunno how to change back though."

Dipper sighed. "Wendy, I don't think any of us _can_ change back."

She merely shrugged. "Oh well." There was that laid back attitude again, both endearing and impossible. "So, what are you, anyway? A deer-centaur?"

Dipper shook his head. "It's called a cervitaur. But yeah, close enough."

She turned to Grunkle Stan and gasped. "Whoa, that's sick! You're a gargoyle? Fang bros!" She laughed.

Grunkle Stan just blinked. "Kids these days and their crazy language," he grumbled. "I'll never understand them."

"Wendy! In here!" Mabel called, leaning on the edge of the fountain.

As Wendy strode over to her, Dipper's heart sank. He wished he could be as carefree as Wendy, but how could he when they were stuck like this? Could they continue living this way? No, he _had_ to find a cure.

"Hey dudes!" Dipper turned around to see Soos heading toward them, a grin on his face.

"Soos!" From far away he seemed normal...until Dipper took a closer look and realized that he was _literally translucent._ He left a trail of yellowish goo and had drops of the stuff falling off continuously. Somehow even his clothes had been incorporated into his new form. As usual, he was completely at home with everything.

"Dipper! You're a lot fluffier than I remember," he said, narrowing his eyes and attempting to scratch his chin.

Dipper sighed. "Yes, Soos. I'm part deer now."

He then tried to snap his fingers, causing goo to fly everywhere. "So that explains it! This is totally nuts, dude. Did everyone wake up all different this morning?"

Dipper's shoulders sagged as he replied, "Pretty much. I mean, there are probably some people who didn't buy the water yesterday, but..."

"Buy the water? You mean Mabel's water?" Soos asked.

"Oh! Uh, no, nevermind! Forget I said anything," Dipper said quickly, forgetting that Stan was going to cover for them.

Soos waved a hand dismissively. "Nah, don't worry about it. I knew something was different about that stuff, but it was so good I had to keep drinking it. I just didn't expect something like this to happen," he chuckled.

Dipper breathed a sigh of relief. "So, you're not mad?"

"Mad? No, nothing like that. Don't worry dude, whatever this is, I got your back." He patted Dipper's shoulder affectionately, covering it in slime.

Dipper smiled up at him. "Thanks, Soos." He really hadn't changed.

Grunkle Stan walked over to them and inspected Soos closely. "All I'm worried about is whether or not you can work in this condition." He prodded Soos's arm, pulling away a string of slime before wiping it on his pant leg. He'd cut holes in the back of his suit's shirt and pants to accommodate his wings and tail, and was none too pleased about it.

Soos stood up straight, giving him a gooey salute. "Don't worry Mr. Pines, my duties as a mechanic shall never be hindered by such a trifling impediment."

Stan grinned. "That's what I like to hear."

Three high pitched screams in unison split the air, causing Dipper to claw at his ears. The reunion had begun.

Grenda and Candy had arrived at the scene, and were now standing over the water fountain. Well, Grenda was standing, Candy was sitting on her shoulders. Grenda had been turned into a crocodile-type-thing, covered in green scales with a long spiked tail and sharp teeth. Her eyes were slit-pupiled and yellow. Candy had become a squid, with black rings around her eyes, hair turned into a black squid head and tentacles for legs that wrapped around Grenda's shoulders.

Dipper, Soos and Stan exchanged glances before heading to the fountain.

"I don't believe it! You guys were turned into water creatures too?!" Mabel was saying in delight.

"You know it, girl! We totally need to hang out in the lake sometime!" Grenda bellowed.

Candy adjusted her glasses. "Yes, that would be most enjoyable."

Just then, the sound of voices and many moving feet pervaded through the buildings. People were beginning to leave their homes, confused, and merging in the town square. Soon a huge crowd had gathered, everyone chattering hurriedly and growing in volume.

Dipper shrank against the fountain, and the others turned to face the crowd, worried looks on their faces. The mass panic guaranteed to follow would not be good.

Soon the crowd gathered by the fountain, spotting the Pines family and their friends, converging to find some sort of explanation. They knew how much trouble the family got up to, as well as how much they'd solved. The people had become all sorts of varying shapes, sizes, colours, and even number of heads. Their voices began to rise in volume, some asking for help, others turning to blame. As the mass pressed in on them, Grunkle Stan stepped forward, raising his hands and silencing the crowd.

It was time to give the people exactly what they wanted: an explanation. And he knew precisely how to tell them.


	5. Chapter 5

Grunkle Stan wasn't one to beat around the bush.

He was the kind of man that would tell you exactly what was on his mind, even if it meant hurting your feelings in the process. Of course, when it came down to whether or not he'd end up in jail, he would say anything to get out of such a predicament and wriggle free from a police officer's grasp. However, it was a whole different ball game when it came to his family. Even if he was known as conniving, cruel, and an overall despicable human being (maybe minus the human part as of late) there was little he wouldn't do to protect those he cared about.

Which is why at that moment, standing before an angry mob of confused and odd-looking people, he told the biggest lie of his life.

It started off with Dipper and Mabel, pure as angels, collecting water from a nearby stream to give to the thirsty people on a hot day. Suddenly, out of nowhere, a pack of horrible gnomes had seized the opportunity to poison the water with a curse from an evil witch dwelling in a nearby cave. With his wild arm gestures and hushed tones raising to crescendos he captivated the audience in his tale. The crowd ooh'd and gasped, and even gave boos of sadness when he pointed to Mabel, the poor child left unable to walk, and Dipper with fur in unfortunate places. After expressing his utter sadness about the situation, he stood up straight and declared that he, no matter what stood in the way, would find a way to set things right. He would find the source of the problem, and punch it into next week.

The crowd cheered as Stan took a bow, and as he made to turn back to the fountain, a voice called his name.

"Stan Pines!" From the mass of people stepped forward Sheriff Blubs and Deputy Durland. They (somehow) had been combined into a two-headed lizard, complete with long necks, silver scales, and two slithery tails. Their individual faces on two necks of the same body was incredibly unnerving.

Behind them followed the new(ish) mayor of Gravity Falls, Cute Biker. He seemed to be one of the few that had avoided the magic water, which was surprisingly boring, and still wore his _MAYOR_ sash he'd won at the election. Which, by the way, was four years ago. Scowls adorned all three of their faces.

Stan eyed them warily. He'd had many close calls with the two officers. He glanced back at Dipper and Mabel. Their eyes were wide, in part due to amazement and in part fear for their Grunkle. He faced the town once again, squaring his shoulders. He wasn't about to go to jail again all because of some stupid water.

Sheriff Blubs spoke, "Stan Pines, your tale moved us. With your words, you started a fire of passion in all our hearts to take revenge on those gnomes and remove this curse. Which is why, with the consultation of our mayor, we are appointing you as head of the Gravity Falls Normalization Program, or GFNP for short."

The mayor nodded seriously.

The Pines blinked in shock. Not only had he pronounced G.F.N.P as if it were a word rather than an acronym, but they'd elected _Stan_ to be the head of this program. Slowly, a grin spread across Stan's face. He would make good use of this power.

He stepped forward and shook their hands. "I would be glad to be given complete power over this program and thus the future of the townspeople's lives." He turned back to the twins and gave them a thumbs up.

Their open mouths turned to smiles as they reciprocated the gesture.

"In that case, Mr. Pines, we'd like to see you at the town hall by three o'clock this afternoon. We'll figure out a plan there," Sheriff Blubs finished. Deputy Durland giggled and rang his bell happily. With that, the crowd dispersed, everyone chatting excitedly. The people had a figure to look up to and trust in to solve their problems. And while it wasn't someone they ever would have expected, Stan had certainly proven himself time and again that he'd do anything for his family- and in turn, the town.

Letting out his pent up breath, he ambled back to where his family was standing. "Well, that happened."

The twins, Wendy, and Soos gathered around him excitedly. Soos slapped him on the back, leaving a great deal of slime, while the rest applauded his success.

"Grunkle Stan, that was amazing!" Dipper cried.

Mabel nodded excitedly. "Yeah, after how the elections went we thought that'd end up a total disaster!"

"Hey, easy now," Stan grumbled. "When you two are involved, it's a completely different story." He smiled at them all affectionately. "Now, who wants lunch?"

All four of them raised their hands. Mabel dragged herself onto Dipper's back, with Wendy's help, and together they began heading back to the Shack, grins of relief on their faces.

"Dipper! Wait!"

A familiar voice called out to them as they were leaving the square.

Dipper turned and Mabel- from his back- poked her head out from behind his questioningly. He told their friends to go on ahead. This could take a while.

Pacifica was galloping toward them- yes, galloping. She'd been turned into a centaur with a golden coat and a long, flowing tail. Like Dipper, her ears had been replaced with that of a horse. Not only that, but a silver horn rose from her forehead, between her bangs. An envelope was clasped in her hand.

She came to a halt before them, panting. Holding out the envelope to Dipper she wheezed, "got you that thing you wanted...the treasure hunting whatever," she looked around distractedly. "Hopefully they didn't realize I left," she muttered.

Dipper took it from her, blinking. "Thanks, Pacifica. And who? Your parents?"

She nodded. "They'd throw a fit if they knew I was showing myself in public 'looking like this'," she scoffed. She took in the Pines' appearances. "Well, you three, uh...certainly look different," she said, her eyes shifting to Stan nervously.

Dipper chuckled. "You look different yourself. A unicorn, huh? I suppose that suits you in a way."

She looked at him irritably. "Yes, well, I've heard about their...antics, that they get up to."

"Oh, no, I didn't mean-" he sighed, rubbing his forehead. "Never mind."

"Pacifica, you look great!" Mabel intervened. "Dipper's right, unicorns are mysterious and beautiful. It suits you very well."

Pacifica blinked. "Thanks, Mabel." She seemed to realize she was falling back into old habits and rubbed her temple, frowning. "But, anyway, my parents are a lot worse off. My mother was turned into a kappa and my father a donkey kind of...thing. It's not like you or me," she said to Dipper, "his body is still human but his head..." she sighed. "Let's just say he's _very_ angry about it. He'd do anything to change back."

"So...he doesn't blame us for this?" Dipper asked warily.

"Oh yeah, he definitely does. He sent one of the servants into town to see what was going on for him since he doesn't want anyone to see him in public." She rolled her eyes. "When he got the news, he wasn't exactly happy that your great uncle is the one put in charge of the change. Regardless, he's going to lend his support if it means fixing this. And so will I."

Stan scowled. "How in the heck did he get wind of that so fast? The speech was practically five minutes ago!"

Pacifica looked up at him. "Well...our servants are very efficient." She turned back to Dipper, crossing her arms. "Now, want to tell me what _really_ happened?"

Dipper winced. He knew that story wouldn't fool her.

She listened intently as he recounted the tale, describing the properties of the river and how he and Mabel had come to discover it. He also mentioned the stone that had supposedly enchanted it, and her eyes widened. "This stone...enchanted by a nymph?" She smiled at them. "I think you'll find that document more helpful than you thought." She looked around quickly, unease clear in her features. "Thanks for telling me the truth, but I'd better get back home before they realize I'm missing." With a flick of her hair and a swoosh of her tail, she galloped away.

Grunkle Stan narrowed his eyes. "Well, she's changed... Is it a trap?"

Mabel giggled. "Of course not, Grunkle Stan! Give people a chance! She's like totally a great person now!"

"I don't know if I'd go that far, but yeah, she's definitely changed." Dipper frowned, recalling what she said about the envelope. He'd have to investigate as soon as he got home. He looked up at the two. "Anyway, lunch, right? I'm starving!"

By the time they arrived at the Shack, it was early afternoon. A cool breeze had picked up, rustling through the trees and bringing the scents of the forest to Dipper's nose. His sense of hearing and smell had both sharpened considerably, and he was having trouble getting used to it. He jumped at every loud noise, convinced it was happening right next to him only to realize it was actually further away. While he could swivel his ears to pinpoint noises more accurately, it was hard to dismiss the tendencies he'd grown up with in exchange for these new advantages.

After a nutritious lunch of salad- Dipper refused to eat meat since he didn't know what would happen if he did- he made his way up to his room.

The room, as always, was divided equally, the left half for Dipper, the right for Mabel. Mabel's side was covered in girly indulgences- from magazines, to make-up, to fluffy hand-made pillows. She had posters of boy bands all over her wall, as well as a couple of her female athlete idols. Dipper's side, on the other hand, was a haven for the intellectual. There were papers scattered all over his bed, covered in notes and scribbles, books on the bedside table, a tray of chewed pens, and graphing paper for Dungeons Dungeons and more Dungeons.

He clopped over to his dresser, removing a fresh undershirt (in the hurry to leave for town he'd forgotten to change his clothes) and took off his hat. Somehow his pants had disappeared rather mysteriously while he'd been asleep, not that he needed them anymore. After disposing of his old one, he pulled on the new undershirt. Over that he wore his blue flannel shirt, unbuttoned and sleeves rolled up at the elbows, and finally rearranged his hair. His hands met with two lumps on his head. Frowning, he explored them with his fingers. Either he'd managed to hit his head in a very peculiar fashion, or he was growing antlers. After arriving in front of a mirror and confirming that they were indeed antlers hidden beneath his hair, he realized with a start that it was the first time he'd looked at himself properly since he'd been changed.

His deer half was the same colour as his hair, with gentle white spots scattered around his rump and tail. He imagined they'd fade away with age much like freckles in skin do. White fur adorned his underbelly, coming up short of where his human half began. He was big enough that a person about Mabel's size could ride him without much issue, but any larger than that would quickly become a problem. His rather large ears had a full range of motion that twitched constantly to catch sounds, as well as reflected his emotions. He was an open book.

Sighing, he put his cap back on and headed downstairs. He took care not to slide all the way down as he had the first time. He found Mabel back in her 'Mabel-tank', as she called it, leaning with her arms over the edge, texting on her phone. Good thing it was water-proof.

She looked up at him as he arrived. "Hey, bro-bro! Candy and Grenda are wondering if we can meet them to go swimming in the lake!" She waved her phone at him, showing him the text.

Dipper glanced wistfully at the table where the envelope sat, tempting him, then back at Mabel. She was looking at him excitedly, tail fluttering through the water. He could tell how tired she was of being crammed in a tank and rendered immobile. She deserved to get some freedom, and he could always read the documents by the lake.

Smiling, he walked over to the table and picked up the envelope. "Of course. Need a ride?"


	6. Chapter 6

Dust billowed around Dipper's hooves as he clopped along the winding dirt road, Mabel perched on his back. Birds sang from their branches in the towering red cedars around them, others flitting about, weaving through trees. The forest was alive with wildlife going about their daily business, the unseen mythical creatures hiding in its depths. The sun bore down on them, forcing Mabel to drink from her water bottle often to remain hydrated in the summer heat.

They were making their way to the lake to meet Candy and Grenda. Mabel and her friends had plans to hang out in the waters, seeing as how they were all aquatic creatures, and have some good old fashioned girl talk. Dipper, on the other hand, had some investigating to do.

Grunkle Stan had left early for his meeting with the officers, saying there were some things he wanted to take care of first. Unfortunately, he didn't elaborate on what exactly he meant by that.

It hadn't even been a day since the whole situation blew up, and Dipper's anxiety about the future was only worsening. The journal had been virtually useless in providing them information about their predicament, and if they couldn't find a way to change back before the end of summer they wouldn't be able to go home. How could they bear to face their family in such a state? They certainly wouldn't be able to continue their schooling in California. To get any sense of belonging they'd have to stay in Gravity Falls, where _everyone_ was different, and adjust to life away from their parents. Dipper shuddered. As much as he loved the town, the Shack, and the mysteries to solve, he couldn't bear the thought of leaving his parents and normal life behind because of a stupid magic river.

Sighing, Dipper shoved the negative thoughts from his mind. Worrying about it wouldn't do him any good. If he were to find a cure, it'd be without the journal's help and by his own wit.

"Dipper, do you think we'll ever change back?" Mabel asked quietly.

Dipper grimaced. So much for putting the issue out of mind. He took a deep breath and tried to give a positive answer. "Well...the journal didn't have anything to say about one, but we can't give up hope. The author can't know everything. There must be something out there that can tell us more, I just don't know what it is yet. I'll find a way to let you walk again. Okay?"

He couldn't see it, but he sensed her nod. The end of her tail brushed against his foreleg gently. After a few moments of walking in silence, Dipper squared his shoulders and decided to lighten the mood. "Say, at the rate we're going, it'll take a while to get to the lake, don't you think?" He'd wanted to see exactly what he was capable of since his transformation, especially now that he was finally comfortable and walking easily. It was time to go for a sprint.

He sensed Mabel perk up. She wrapped her arms around his torso, knowing exactly what he was planning. She said into his shirt, "go for it, bro-bro."

Dipper began to pick up pace, going into a trot, then full-out gallop. He veered off the path and into the trees, cutting through the woods straight to the lake. The freedom he felt and confidence in his ability was astounding. He ran faster than he thought possible, the wind rushing through his hair as he zigzagged between trees and leaped over logs and bushes. The greenery rushed by them in a blur as he flew past it, fluid and graceful. He was hyper-aware of everything around him, processing obstacles in his path and darting around them on instinct before even fully realizing they were there. He could trust his strong, capable legs to take him precisely where he wanted to go and doing it in record time.

Before long, they burst out of the trees and skidded to a halt by the lake, nearly causing Grenda and Candy to jump out of their skins.

Mabel released her death grip on Dipper and threw her head back, laughing hysterically, hair in complete disarray. "That was AWESOME! I mean, I almost died, but holy moly! We got here in like, two minutes!"

Dipper crossed his arms proudly, catching his breath. "Yeah, that was pretty cool. Hey guys," he said to Candy and Grenda, who were still processing what happened.

They were both decked out in swim wear. Swim wear that made accommodations to their slightly monstrous appearances. Smiles crossed their faces.

"About time you got here!" Grenda bellowed. "We're gonna have like, the best swimming contest ever!"

Mabel rubbed her hands together excitedly. "Ooh, I like the sound of that! Come on girls, to the water!"

"To the water!" They cried. Grenda proceeded to pick Candy up, run to the edge of the pier, and throw her like a football into the lake. She followed with a scaly "CANNON BALL!" generating a huge splash.

Dipper followed more delicately, lowering Mabel to the water so she slipped into it gracefully. She surfaced, giving him a thumbs-up. "Thanks for the ride, Dipper!"

He grinned. "No worries. Have fun," he said, standing. His hooves thumped hollowly against the pier as he headed back to shore. Walking around the perimeter of the lake, he found a spot on a slightly elevated position between the trees where he was alone but could clearly see Mabel and her friends. They shrieked with laughter, splashing about and gliding through the water with ease. He could see Mabel's grin from where he was standing, and it made him smile softly. It was good to see her adjusting so well. The sun glinted off the water, and the cloudless sky gleamed blue. Seagulls dotted the water and the shore, squawking to one another. Many other townsfolk that had been transformed into aquatic creatures inhabited the lake as well, and some swam while others drifted aimlessly. Everyone was clearly still getting used to the problem.

He settled down into the grass, pulling out Pacifica's envelope and reaching inside.

The contents were a list and documentation of stolen items by a man named Clinton Northwest (1828-? location unknown after mysterious disappearance), the treasure hunter of the Northwest family. He'd uncovered a great many valuable treasures scattered throughout not only the United States but Europe and Asia as well. There were sepia-toned photographs that depicted him standing before St. Paul's Cathedral, the Great Wall of China, and many other famous landmarks besides. Dipper marveled at this fact alone considering the amount of time and money it cost to set out on a voyage across the Atlantic Ocean back in the day. Unless of course he'd been a stowaway.

Dragging his eyes away from the photographs, Dipper returned to the list. Pacifica said that he'd find the document more helpful than they realized after he'd mentioned the stone. That meant this man had something to do with it. Perhaps he'd stolen it himself.

Scanning through the numerous names of treasures, a couple of them highlighted for interest, one caught his eye. 'Nymph's Spite' it read, the number 108 written next to it. Flipping through the next set of documents, a yellowed many pages bound by string, he arrived at the one hundred eighth and final entry. Upon reading it, Dipper realized Clinton Northwest was slightly insane.

'Confound it all! Those nymphs are cleverer than they look. Especially _that_ one in particular. All I asked was a peek at the stone, and what does she do? Curse it so that as soon as I go to steal it I'm transformed into this...this abomination! I always thought the jackalope was mere myth, but mere myth it is no longer. I can't let my brother see me like this, he'd never let me live it down. Or disown me entirely. The grouser would make me the laughing stock of Gravity Falls...

To think there'd be such an artifact so close to home. I've finally gotten my hands on it too, but because of this blasted curse, it's worthless! I'll have to bury it somewhere so it doesn't affect anyone else...' After that, the smudged writing became illegible.

Clipped to the back of the sheet was another piece of paper, torn from what looked like a journal, showing a dated entry written in a flowing hand. It was a random blurb of Clinton's scuffle with a savage barmaid from Transylvania, but what really interested him was the fact that the man owned a journal. A journal that perhaps was still hidden in the Northwest mansion. If he could find it, maybe he could also learn the location of the buried stone. Sense told him that it would be around the Fluvius Cantatis, but the river stretched pretty far. He had no idea where along it could be hidden. Perhaps he could map out the area and find some possible locations...then talk to Pacifica and see if she knew anything about the journal.

Wrapped up in his thoughts, he nearly jumped into the lake with fright when a voice behind him cleared its throat rather obnoxiously. Shooting to his feet and whirling to face the speaker, he let out a groan when he saw none other than Lil' Gideon. He'd been turned into what looked like a vampire. At least, he certainly dressed the part. He wore a cape with a collar that rose above his head and halfway up his white pompadour, which was saying something, and his trademark blue suit with pointy shoes. He'd grown maybe an inch in the past four years, but other than that he looked exactly the same. He stood with one arm draped before his face like a classic vampire, eyes glinting evilly over his wrist. One of his cronies from prison was situated behind him, holding a parasol above Gideon's head, shielding him from the sun.

Dipper rolled his eyes. He'd dealt with this little twerp enough for a lifetime. "Shouldn't you be in jail or something?"

Gideon blinked, clearly taken aback. "That was four years ago, _Pines_. I've been set free. I can do whatever I want now," he growled, Southern accent as strong as ever.

Dipper inspected his nails, giving a bored impression. He'd learned that the best way to deal with Gideon was to not give him the attention he wanted. "Oh? Sorry, I hadn't noticed. Well, for the moment, perhaps you're better off kicking a puppy or stealing candy from a baby. Those kinds of boringly predictable stunts seem to be your area of expertise, after all. Careful though, someone might think _you're_ the baby and steal from you instead."

Gideon narrowed his eyes and looked like he was about to give a retort before thinking better of it. He merely chuckled instead. "Clever as always, I see. But enough of that, I didn't come here to pick a fight with you. I just wanted to see how you were holding up. So, you're some kind of deer-centaur, huh?"

Dipper grit his teeth. "Cervitaur."

He waved a hand dismissively. "Yes, yes, well. Not everyone was as lucky as me, it seems." He grinned, exposing his long canines. He pointed to the envelope in Dipper's hand. "So I take it you've found your first lead on finding a cure? The stone enchanted by a nymph?"

Dipper stared at him. "How did you-"

"Let's just say someone tipped me off. But see here, Pines. I don't think I want you to find this...cure. I quite like the way I am, and I don't need you going ahead and messing it up for me. Being a vampire has its perks, after all."

Dipper narrowed his eyes at him. Why did Gideon care so much whether or not they found a cure? Did he think they'd force it on him as well? Then again, seeing as how he was a vampire and Dipper _really_ didn't want to have to deal with one of those, he was probably right for thinking so. Or maybe, knowing Gideon, he had an ulterior motive. If that was the case, Dipper was determined to find it out. "Really, that's it? You don't want us to find a cure? You're not here to try and steal Mabel again?"

Gideon chuckled. "Oh, I don't think I'll need to steal her this time. I think she'll come willingly. She loves vampires, after all."

Dipper snorted. "Yeah, the 'hot kind'. Which you most definitely are not. There's no way Mabel will like you. Not now, not ever."

Gideon quivered with rage. He'd touched a nerve. "Silence!" He shrieked, making Dipper flatten his ears. "I will stop you from finding that cure, you hear?! I'll make sure this change is permanent and take Mabel as my mermaid bride. Just you wait and see, _Pines."_ With that, he snapped his fingers and melted into the shadows, prison buddy close behind.

Dipper sighed, rubbing his forehead. With Gideon watching his every move, finding a cure wouldn't be easy. He glanced down at the envelope in his hand. He'd need to come up with a plan.

* * *

 **Gideon's finally made his appearance :O Anyway, I may need to come back and make some changes to the chapters as I upload more since I'm at a critical point in planning. If I do I'll mention it in future chapters.**


	7. Chapter 7

Mabel cut through the water, gliding along gracefully. The coolness of the lake which would have previously chilled her now felt calm and refreshing. She closed her eyes for a moment as she twisted around, floating on her back, allowing the sun to shine on her face. She finally had a chance to swim freely and learn what her new body was capable of, and she was enjoying every minute of it. She'd easily trumped Grenda and Candy at their little swimming contest, proving to be the quickest and most agile of the three.

This whole state of affairs had put Mabel in a bit of a conundrum. As much as she wanted to be able to walk again, she couldn't get over how _cool_ it was to be a mermaid. Of course she wanted them to revert to their normal selves so they could go back to California at the end of summer, but for the meantime she planned to enjoy it.

Grenda splashed water over Mabel's face, snapping her out of her reverie. Giggling, she righted herself and returned the action.

"What's the matter? You look almost _too_ happy!" Grenda told her jokingly.

"Well, you know me! Making the best of every situation is what I'm good at," she replied, smiling.

Candy swam over to them, tentacles propelling her along easily. "This problem could have ended up a lot worse," she remarked. "We are lucky to have gotten off so easily."

Grenda nodded in agreement. "Yeah, it's not so bad. I don't really care if we change back or not. This is pretty cool! Right, Mabel?"

Mabel bit her lip uncertainly. She glanced down at her tail as she tread the water. Since she was little she'd always loved swimming, and she could definitely get used to spending all day in the water...but for the rest of her life? She thought about Dipper and his endeavors, and realized that she would no longer be able to accompany him in his mysteries. At least, not without being a serious liability. He'd have to carry her wherever he went, and she could no longer run around and do the things she wanted to. Sure, she had more freedom in the water, but what did that amount to compared to freedom on land? Her shoulders sagged sadly. Maybe she _did_ want him to find a cure soon. Or at least a way for her to get around on land more easily.

Grenda and Candy looked at her questioningly. She opened her mouth to speak when she heard someone call her name. Looking back to shore, she noticed Dipper cantering around the edge of the lake, holding the envelope and making his way to the pier. As she began to swim to greet him, he stopped and turned around suddenly to see Grunkle Stan pull up to the lot in his car, calling his name through the window. His wings were crammed in the tiny space before he pulled himself out and stretched gratefully, wings flaring impressively. He beckoned Dipper over quickly, to which Dipper obeyed with a backwards glance at Mabel. They discussed something hurriedly, Dipper's erratic gestures betraying his impatience. Once Stan was satisfied, he stepped back to the car while Dipper trotted over to the pier. Mabel floated in the water, grasping the edge of the wooden boards.

Dipper's ears were pricked with excitement as he said, "Mabel, I think I found a lead on the stone! You know, the one that made the river magic? If we can find it maybe we can reverse this spell somehow! I'll need to ask Pacifica about it and chart out some locations..." He got that distant look in his eyes he always had when he was making some sort of calculation or solving a problem. Then he snapped back to reality. His ears drooped slightly as he said, "Also, I just had a run-in with Gideon."

Mabel gasped. "Gideon? I almost forgot we sold some of that water to him...how did he turn out?"

"Bad," Dipper said bluntly. "Well, bad for us. He's a vampire now."

Mabel shivered, repulsed. She always loved the fantasy of attractive vampires, and the fact that _Gideon_ was now one put a bit of a damper on it. She didn't know much about how vampires were in real life, but hopefully he wasn't as powerful as some of the ones in fiction. "Well, that's just great."

"Yep. Even worse, he's taken a liking to it...he doesn't want us to find a cure." Dipper faltered as a certain gravelly voice called his name impatiently. He sighed. "Sorry Mabel, gotta go. Grunkle Stan wants me to do calculations for a project he's starting on as head of G.F.N.P. Are you okay here?"

Mabel nodded, put out slightly. She wanted to see how things would go over with Stan and this movement, but she supposed she'd have to hear it from Dipper later. She waved goodbye as he galloped over to where their Grunkle was standing. Dipper opened the door to the car and got in awkwardly, folding his back legs so he sat on the seat with his front legs stretched out before him. He gave Mabel a thumbs up, who giggled as they pulled out of the dirt parking lot and disappeared behind the trees.

She swam back to Candy and Grenda dejectedly. "I don't know, girls," she said, answering their earlier question. "I like being a mermaid and all, but it's just...what about Dipper? I can't follow him and help out as easily anymore! Not to mention Waddles...he'll miss those adventures we go on for sure. I just don't have the freedom I used to." She sighed, looked at her friends' crestfallen faces, and mentally scolded herself. She was supposed to be the cheerful one! Upsetting her friends wasn't part of her system! Now that she was here with her two best friends there wasn't any point in spreading her sadness to them. She raised her head and gave them her biggest smile. "You know what? Let's not worry about that now. Let's go exploring!"

Candy and Grenda instantly brightened. "Yeah!"

The trio then spent the afternoon exploring the bottom of the lake. Mabel's powerful tail propelled her along gracefully, making quick turns, doing loop-de-loops and shooting through the water with ease. After some hesitation she realized that she could breathe underwater just as easily as she could on land. She finally felt unhampered since they'd woken up that morning, and was completely in her element. On top of that, she and her friends now had the ability to process sound vibrations through the water almost as if they were on land. This meant that they could communicate without issue while in the deepest recesses of the lake.

The water was surprisingly clear, exposing the bottom easily. Many different aquatic plants grew from the shifting silt, and many shells and other collectables littered the area. Random items that people had thrown in or lost were also visible, and Mabel picked up one in particular. It was covered in underwater moss and little shells, but once she brushed them away she recognized it instantly. It was one of the many disposable cameras Dipper had bought years ago to capture the image of a terrifying sea monster to win a contest. Mabel smiled at the memory. She remembered fondly the annoyed look on Dipper's face when she teased him, threatening to toss the cameras overboard.

The girls searched the lakebed for shells and shiny items, looking for things that would make suitable pieces of jewelry. They then sat on boulders near the edge of the lake as they began to piece together the shells into necklaces, using an emergency storage of thin twine Grenda kept with her for reasons like this as string. They told stories and talked about boys as they worked, laughing and enjoying each other's company.

"So, spit it out," Grenda said to Mabel as she strung together her necklace. It consisted of red and orange shells, as well as shiny baubles she'd found in the silt. "Who's the lucky guy this year?"

Mabel giggled. "Well, I don't have anyone right now, but there was this one guy at the beginning of the school year...oh, he was _so_ dreamy! I wish I had a picture to show you. Anyway, we went out for a couple weeks, thinking we shared all the same interests and had a great time... But then one day, when were out at a restaurant, he outright told me he didn't like pigs! Can you imagine?"

Grenda gasped in disgust while Candy shook her head disapprovingly.

" _Right?_ You girls get it! Needless to say, I dumped him immediately. Since then, no one else has really come by," Mabel said sadly.

Grenda thumped her back in a somewhat reassuring manner. "That guy was a loser! Don't worry Mabel, someone else will turn up."

Mabel smiled at her gratefully. "Thanks, Grenda. How are things going with you and Marius?"

Grenda chuckled. "Well, you know how he is. He keeps wanting me to visit for the summer, but I keep telling him I need to hang out with you guys! That always makes him kind of upset. I still visit him during winter break though. He takes me on these tours of his castle..." her voice trailed off as she sighed dreamily.

Mabel giggled. "I'm glad to hear it. How about you Candy?"

Candy shrank back, blushing, but didn't say anything.

Mabel ooh'd and Grenda barked with laughter. "Apparently she has a thing for your brother again," she told Mabel.

Mabel gasped, a grin spreading across her face. She remembered back when they were twelve Candy had a crush on Dipper, and Mabel totally shipped it. Unfortunately, it didn't last very long. "No way! Again? When did this start?"

Still blushing, Candy whispered, "Just recently. He has gotten so dreamy! Not to mention when we saw him running through the forest so majestically..." she sighed, practically falling off the rock with her swooning.

Mabel snorted with laughter. "So, you like him since he became a cervi…cervitaur thing?"

Candy shrugged. "Maybe a little before that. I'm not sure."

"Well, that's good enough for me! Too bad he's gonna be so busy with finding a cure and everything, otherwise I'd totally set up a date for you guys!" Mabel said regretfully.

Candy shook her head sadly. "It's okay, I thought he would try and find one. He is always dashing about doing something. He doesn't have time for someone like me." Mabel patted her shoulder, assuring her that wasn't the case.

Soon they moved on to other subjects, finishing their jewelry and wearing it proudly. They continued their swimming, enjoying their time together as best friends.

Later, Mabel decided to explore deeper into the lake. She saw Scuttlebutt Island ahead of her and the twisting black depths that surrounded it. Warily, she swam closer, eyeing the dark waters. It was noticeably colder here, making her shiver. She spied movement below her and squinted, trying to make out what it was. It moved again, angling slightly upward this time, and a long, green, scaly tail became visible. It snaked forward and disappeared into the darkness. A deep rumble from the throat of a great beast reverberated through the water. Mabel gulped and swam back to Grenda and Candy, heart pounding. She wouldn't go near that place again.

She surfaced to see the two floating near the pier, glancing around before spotting her and beckoning. Mabel glided over to them to see Dipper clopping his way to the edge of the pier, waving.

"Dipper!" She smiled, waving back.

"Hey Mabel," he grinned. "Grunkle Stan asked me to come get you. It's almost supper time after all."

Mabel blinked, looking around. He was right; the sky had taken on an orange tinge, the sun beginning to dip behind the trees. "Wow, I never even noticed! We were having so much fun we forgot to keep track of time," she said, smiling at Candy and Grenda. Candy had partially submerged her head to hide her red face in the presence of Dipper, and Grenda was struggling to hold in a laugh at her friend's expense. The two nodded in agreement.

"I'm glad you guys had fun," Dipper told them. "But we'd better get back before Grunkle Stan gets impatient. He wants to tell us how his meeting went over. Let's get home."

After waving goodbye to Candy and Grenda, the twins began the journey back to the Shack. As he walked, Dipper filled her in on the details of the envelope. He told her about how Clinton Northwest had stolen the stone that he called 'Nymph's Spite' due to its ability to transform the holder, and how he owned a journal that by a stretch of luck could still be hidden in the Northwest mansion.

Dipper practically pranced with excitement, ears and tail quivering. "This is great! Maybe a cure isn't that far off after all!"

Mabel grinned, nodding in agreement. "Once I get my legs back we should totally check out those other things this Clinton guy discovered! Maybe he has some other buried treasure we could find nearby..." she rubbed her hands together excitedly.

Dipper chuckled. "Sure thing, Mabel. We've still got the rest of summer after all."

Mabel stretched her arms. "Yup! We've got tons of time! So anyway, how did Grunkle Stan's thing go? What did he have you make calculations for?"

Dipper scratched his head as they arrived at the Shack. "Well…I think you'd better have Grunkle Stan explain that one to you. It's kind of complicated."


	8. Chapter 8

As the twins opened the door to the Shack, they came face to face with Soos, as gooey and drippy as they remembered.

Dipper yelped in surprise, Mabel laughed and waved from her spot on Dipper's back. "Hey Soos!"

Soos smiled, the room behind him visible through the shifting slime. Somehow his ball cap, question mark t-shirt and shorts were all part of his new form. "Oh, hey dudes! You gotta see what I'm working on!" He beckoned them inside, loose gobs of goo flying from his arm.

Wendy waved a clawed hand as they passed her spot at the register, glancing up from her magazine and giving a toothy grin. A few customers milled about the gift shop, glancing at its employees nervously. The show room was shut, a sign hanging from the door reading 'CLOSED FOR REPAIRS. SORRY DUDES!' As Soos opened the door and led them inside, Dipper noticed that any slime that had fallen off or trailed on the floor behind the mechanic began to form spheres and roll back toward him of their own accord, returning to their source. They approached the back of the show room and Soos cleared his throat, presenting the object before him. "Behold: the Mabel-tank 2.0!"

Standing in the corner was a large, water-filled, oval glass tank, standing about five feet tall. It sat on a thick wooden plank with sturdy wheels nailed to the bottom. The contraption was hooked up to a small electric motor, a wire running up the side and attached to a joystick taped to the rim. Any exposed bits of wire or metal was tightly bound in electrical tape, ensuring Mabel wouldn't electrocute herself while operating it. A tap stuck out the side of the glass, allowing easy draining. It was all very Soos-like in engineering.

Mabel gasped in wonder as she beheld the contraption. "Soos, this is amazing! How did you make this?"

Soos adjusted his cap solemnly. "A mechanic never reveals his secrets. Anyway, wanna give it a try, Mabel?"

She nodded vigorously. Soos hoisted her from Dipper's back and plopped her inside. She had enough room to float any which way, her tail curling neatly at the bottom. With the way her scales shimmered and long hair billowed around her, she looked like she could be one of the attractions. She poked her head out the top, grinning. "It's perfect! Now let's see how this thing moves!" She grasped the joystick and pushed it forward. With a low whirring sound, the tank began to crawl toward Dipper, who backed up in alarm. Mabel laughed. "Anything that spooks Dipper is good enough for me! Thanks, Soos."

He gave her a thumbs up. "Don't worry about it, dude. This should work while you're at home. Dipper can still carry you while you're outside."

Dipper rolled his eyes but nodded.

Mabel beamed at them. "Thanks for all the help guys. You have no idea how frustrating it is not being able to move around on my own." She looked down sadly, sinking back into the water, hair floating about her face serenely.

Dipper studied her expression. He hadn't seen her so discouraged in a very long time. Normally Mabel would always adjust to a bad situation with ease, but he could tell her reduced mobility was really getting to her. It was always her energetic bouncing around that lifted everyone's spirits, after all. And now she was unable to do that. She might as well have been confined to a wheel chair...something the tank closely resembled.

Dipper stepped forward, placing a hand on the glass. He pricked his ears and smiled softly as Mabel met his eyes. She gave a sad smile in return, reciprocating the gesture.

Someone cleared their throat behind them, and Dipper removed his hand from the tank quickly, startled. Their Grunkle was standing in the doorway, tapping his foot impatiently. His ominous form and large wings cast a shadow into the room. "I don't mean to interrupt this touching sibling moment, but can you all join me in the living room? I need to talk with you." With that, he strode away. The twins and Soos glanced at each other before making their way to the lounge. Miraculously, the door frames were just big enough that Mabel's tank could barely fit through them.

A section of the living room floor was covered in a large blueprint of the town, which Stan stepped over carefully as he made his way to his chair. He sank into it gratefully as the twins, Soos and Wendy gathered round. His tail draped over the arm of the chair and he folded his wings as he studied them. "Now, as head of G.F.N.P, I have already begun to implement my first change." He gestured to the map below him. "Because a big chunk of the townspeople have been turned into water...things, I've decided to have canals built all throughout the town." He pointed at the penciled-in lines that ran along either side of the roads next to the sidewalks. They connected to an underground channel that flowed directly into the lake, providing easy access for anyone swimming in them. "This town has always had stupidly wide roads anyway, so I don't see why people would have a problem with it. When we eventually find a cure we'll have some nice fresh water straight from the lake for everyone to use. And if people _do_ complain, they can go suck a lemon for all I care!"

"Yeah! You tell 'em Grunkle Stan!" Mabel yelled, pumping her fist.

Stan grinned broadly at them, exposing his sharp teeth. "Mabel needs a way to get around town without always having to rely on Dipper, right? This is just the way to do it!"

Dipper cleared his throat. "I did all the measurement conversions and helped decide where the canals should go at the conference today." He added under his breath, "It's not like anyone else in this town has a basic understanding of math, after all."

Grunkle Stan laughed. "That's my little genius! He helped me convince the mayor. The Northwests are on board too, since Priscilla Northwest is a turtle thing now." He chuckled. "It suits her, too. Anyway, they'll be paying for most of the construction."

Mabel blinked. "Well, that's generous of them."

Dipper snorted. "It's not like they don't have the wealth to spare anyway."

Stan went through some of the other details of the meeting that day, mentioning the townsfolk's new vendetta against gnomes and colourful lawn signs depicting this fact.

After Stan finished his explanation and rolled up the blueprint, Dipper stepped forward. "I'd also like to share something with you all," he announced. Producing the envelope for everyone to see, he opened it up and showed them the contents. Explaining the treasure hunting past of the Northwests, he mentioned the stone dubbed Nymph's Spite that had enchanted the river and its ability to transform those who came into contact with it. He told them that if they could get their hands on it, they may be able to unlock some sort of secret about it that could change them back to normal.

Wendy scratched her head, frowning. "But if this Clinton guy hid it somewhere and took off because he didn't want to be seen anymore, doesn't that mean he couldn't use it to change back?"

Dipper sighed. "Yeah, that's the problem. But if we can get it, maybe we can find something he missed. It might not be too late. We've still got a shot at this!" He pounded a fist against his palm. "I've already mapped out some locations of where the stone can be hidden. Now I just need to ask Pacifica about Clinton's journal and we may be able to pinpoint its location."

Wendy walked over to him, slinging her arm around his shoulders. After four years Dipper had grown to be about her height, yet she still treated him like her kid brother, something Dipper was content with. "You heard the little man! We've got our first lead!"

Grunkle Stan joined in, rising from his chair and tipping Dipper's hat off teasingly. "The town'll be happy to know we've got our best man on the case. You done good, kid. Still got a ways to go though."

Soos stood before Dipper, hand over his heart in an unexpectedly serious gesture. "You've got my full support, dude. All my abilities as a mechanic will be at your disposal."

Dipper blushed at the praise. "Thanks, guys. I appreciate the support."

Mabel watched fondly from her spot in the tank. It was good to see Dipper getting the attention he deserved. He'd managed to find a lead within a single day of them being transformed, after all- with help from Pacifica of course. Now they had to act on it and turn that lead into a cure. The hunt for the source had begun.

The next week at the Mystery Shack was a busy one. Grunkle Stan had his hands full with overseeing the canals operation, which was progressing along smoothly, and Dipper with studying the river. He took samples of the water and tested it in beakers, exposing it to different conditions and recording the results. Nothing he tried made a difference. He attempted to reverse the spell using the water and incantations he'd read in his journal, but so far nothing changed. He'd told Pacifica about Clinton's journal and offered to help look for it, but she had declined. She said that her family still blamed the Pines for the predicament, and that letting him into the mansion would only worsen her father's mood. She promised to look into it herself. Since then he'd received scraps of information about the possibility of a journal hidden in the mansion but nothing solid yet, and Dipper was getting impatient. His antlers were growing at an alarming rate, and after searching it up he learned with a shock that deer antlers could grow up to half an inch per day. To his dismay he was soon unable to wear his cap, and if they kept up the pace he wouldn't be able to pull a shirt over his head. His stress about the whole situation sometimes left him unable to sleep, and he spent hours awake at night trying to connect the clues or flipping through his journal for information he may have missed. The previous night had been one of them, and he found himself drifting off into a deep sleep by noon.

Dipper awoke to the sound of a loud _thump_. Slowly, he opened his eyes. His face was mashed into his pillow and he was covered in notes. His legs were splayed at odd angles, showing that he must have collapsed into bed at the last second. Sitting up blearily, he looked around, attempting to rub his head before ramming his fingers into antlers. Sometimes he forgot the darn things were even there. Orange light filtered through the window, motion-stirred dust drifting through the beams. It was already evening. The end table was littered with water-filled beakers, more notes, and the occasional stress ball. A cork board hung from the wall above Dipper's bed. Stuck to it were photographs, even more notes, and red string linking relevant points of information together. Yawning, he sat up and pulled his legs into a more natural position, rubbing his back as he stretched. Suddenly, a large dark shape blocked out the sun, hovering just outside his window. Dipper leapt out of bed, backing toward the door. The shape hung there for a moment before falling to the ground with another loud thump and a frustrated yell.

Dipper frowned. What was going on?

He made his way downstairs and exited the Shack, blinking in the evening sun.

"Hey Dipper!" Mabel called. She was floating in the old over-ground pool that now sat in the front yard. Next to her was Stan, sitting on the grass and rolling his shoulder, muttering. Shallow craters scarred the ground.

"What on earth are you guys doing?" Dipper asked tiredly.

"I'm teaching our GarGrunkle how to fly!" Mabel said excitedly.

"Yeah right," Stan grumbled. "You call shouting optimism so bright it could blind a rainbow 'teaching'?"

Mabel shook her head. "Come on, Grunkle Stan! I told you, it's all in the believing. If you believe you can fly, you will!"

"Whoever taught you _that_ nonsense needs a good hard slap from reality," Stan muttered.

Dipper shrugged. "Well, Mabel _did_ teach me how to walk on four legs even though she couldn't walk at all."

Mabel nodded proudly.

"I'm pretty sure walking and flying are two entirely different things." Stan sighed, standing. "Well, I'll try again tomorrow. Come on, Mabel. Let's get supper ready."

"Don't worry Grunkle Stan, I'm sure you'll get it eventually," Mabel assured him as he lifted her from the pool.

"Yeah, well. Maybe I won't need to if we find that cure. The sooner the better," he grumbled. Straightening, he carried her inside, leaving Dipper standing on the grass, alone.

Mabel had been acting as an emotional crutch for both Dipper and Stan. She supported them with her optimism and eagerness, throwing in advice for their personal endeavors. For Stan she gave guidance on what to do for the town and how to make people happy, while for Dipper she helped him with his experiments and research. She had been doing a good job of acting carefree, but Dipper could tell she was still bothered by the fact that she couldn't help out as much as she wanted to. Dipper bit his lip. He wished he could find a way to help her somehow, at least until they could find a cure.

He sighed, then breathed in the fresh air, observing the surroundings. The whole scene was tinted orange with the twilight as the sun began to sink below the trees, the rays diffusing through the branches softly. The shadows stretched long and dark, and the wildlife began to scurry back to their homes for the night. Dipper closed his eyes briefly, enjoying the peacefulness, then opened them again.

He frowned. In that brief instant it seemed the world had taken on a grayish tinge. The sound of chirping birds vanished completely, and a cool breeze picked up. Dipper's ears flattened to his skull. He recognized this feeling. At the edge of his consciousness a ringing laughter began to grow in volume, high-pitched and echoing. He backed up, glancing behind him nervously. He turned back to the trees and came eye to eye with a glowing, bright yellow triangle.

"Hey there, Pine Tree!"

Dipper yelped and staggered back, nearly tripping over his hooves.

The demon laughed at his reaction, closing his eye and waving his cane. "Well, well! You're a mite fuzzier than I remember!" He squinted at him. "And a lot less sweaty."

Bill Cipher. It had been years since he'd last seen the dream demon, and not once did he meet him on good terms. He never showed himself unless he was sure he could gain something, which meant Dipper was in trouble.

Dipper sighed irritably. "What do you want, Bill? You never show yourself for four years and now you suddenly appear out of the blue? What's your motive?"

Bill laughed again. "Just as inquisitive as ever! Personality wise you haven't changed at all, have you? Now your appearance on the other hand...you seem to be in a bit of a pickle!"

Dipper glared at him. "It doesn't take a genius to figure that out."

"Listen closely, Pine Tree," Bill said, ignoring the verbal jab. He floated over to the Shack and sat on the porch, balancing his cane on his...knees? "We may have gotten off to a bad start all those years ago, but howzabout you cut me some slack, huh? I wanna give you a hand this time!"

Dipper stared at him. " _You_ want to give _me_ a hand?"

"Yep!" Bill snapped his fingers, and a disembodied hand popped into existence. It flew toward Dipper, reaching for his face. Dipper yelped, ducking as it flew over his head and disappeared into the trees. Bill laughed. "It'll be one of those exchange things. Y'see, I've been watching you and your sister. For years I've waited for you to discover that stream in the woods...and now it seems you finally have!"

Dipper scowled at him. The demon was up to something yet again. "You knew about the Fluvius Cantatis? Why did you want us to find it?"

"Well, as your book told you, the river was enchanted by that precious little stone that oddball Northwest found. I knew you wouldn't want to find it without needing some kind of motivation, so I had to wait till you got yourselves into this mess to convince you. Because you see, the thing about that stone..." He hovered over to Dipper, resting his elbow on his shoulder. "...is that I want it."

Dipper blinked at him. "You want a magical stone that you can't even interact with? I thought you couldn't touch things from the real world."

Bill snapped his fingers. "Right you are, Pine Tree! But you see, nymphs are tricky. They're an anomaly that no one can seem to figure out! No one but me, anyway. They exist half in the dreamscape and half in the real world. That stone can be used by both living creatures _and_ snazzy mind demons like myself!"

Dipper leaned away from Bill, crossing his arms. "And _why_ exactly do you want it?"

Bill waved a hand dismissively. "Don't worry about the details, kid. The point is, I want you to find it and hand it over to me after you use it to cure your town or whatever. Put that keen sense of smell to good use, huh?"

Dipper shot a glance at him. "So it _can_ cure us?"

Bill chuckled. "Yes, indeed it can. So, wanna help a guy out?"

Dipper almost laughed. "Are you kidding? You show up out of nowhere and ask me to find this stone for you, and for what? You don't have anything to use against me this time, and I've no incentive to help you. You're out of your depth."

Bill narrowed his eye, giving a low giggle that turned into a maniacal laugh as he hovered in front of him. "That's where you're wrong, Pine Tree! I said I wanted to give you a hand, and I intend to follow through. I've seen how...upset Shooting Star is about this whole thing. What if I knew the whereabouts of a certain magical bracelet that would allow her to walk all by herself? Would that be enough?"

Dipper's eyes widened. Something to let Mabel walk again? And Bill knew where it was? Anger bubbled in his chest. That damn demon was using his sister as a bargaining chip! He really was the lowest of the low.

He spoke calmly, "And what if I happen find the stone quickly? I wouldn't need that bracelet anyway."

Bill giggled. "I wouldn't count on it, kid. You'll need her help if you ever want to find that thing. And trust me, it won't be by her flopping around uselessly on the sidelines."

Dipper glared at him but didn't speak. He turned away, staring angrily at the ground. He was at an impasse. If what Bill said was true (and it probably was seeing as how he was omniscient), there was something out there that would allow Mabel to stand on her own two feet again. He could already imagine the grin on her face as she bounced around, back to her old energetic self. And if he needed her help to find the stone, what other choice did he have? He swallowed.

When he turned back to the demon, he was already holding out his hand, wreathed in blue fire. His eye glinted evilly. He knew he'd won.

"The terms of the agreement are as follows," Dipper said shakily. He had to be sure Bill wouldn't trick him again. "You tell me where this bracelet that will help Mabel is and I'll give you the stone _after_ I use it to cure us. Deal?"

Bill's eye narrowed in triumph. "Deal!"

Dipper reached for his hand, but paused last second. "You're not going to possess me again, are you?"

Bill rolled his eye. "Relax, kid. I don't need to mess around learning how to walk with your little deer legs any time soon."

They shook hands. Dipper shivered as the binding contract fell into place. What had he done?

* * *

 **Ermagerd he's finally appeared :O Time to go on a dorito hunt.**


	9. Chapter 9

"Mabel!" Dipper yelled, bursting through the front door.

Mabel was sitting in her tank in the living room, having finished helping Stan prepare supper, and was reading a magazine with her arms stretched over the rim. She jumped when Dipper came flying into the room.

"What?" She cried. "Is it Gideon? Jeff the gnome? That invisible wizard whose name I can't remember?"

"Yeah- wait, what? No, I found a way for you to walk again!" Dipper said hurriedly, standing before the tank.

She blinked. "Whoa, back up. You did _what?"_

He waved a hasty sketch he'd drawn at her. Dipper had always been a good artist, so she recognized the depiction easily. It was a bird's-eye view of the lake, including the waterfall and Scuttlebutt Island. He pointed to a particular part of the drawing, a little circle with rocks jutting out, located near the waterfall and below the water's surface. It was the entrance to an underwater cave.

"So it turns out Mermando wasn't the first mermaid to be stranded in Gravity Falls," he said excitedly. "There was another that inhabited the lake for a while. She got help from some kind of water fairy to create a bracelet that let her grow legs in place of her tail. It's temporary, but the jewelry let her get around easier until she found a way back to the ocean. She hid it in a cave in case another mermaid ever needed it or if she wanted to return to Gravity Falls. If we get it, it'll let you walk on land and we can find the stone together!"

Joy and disbelief grappled for her heart. A smile spread across Mabel's face, then flickered out as she asked, "Wait, so how do you know this? Did you find another page in your journal?"

Dipper hesitated, lowering the drawing. Speaking quietly he said, "Well...not exactly. Bill told me."

Mabel gaped at him. " _Bill_? Why the heck would he tell you that? And why did he finally show up again?"

Dipper recounted the tale, fidgeting as he told her about the agreement he'd made with the demon. He knew she wouldn't like it, but he wasn't prepared for the look of complete and utter horror that donned her face.

"Dipper! You made another deal? I thought we agreed to never do that again!" Mabel whispered frantically, hoping Grunkle Stan wouldn't hear. It'd get messy if he knew what was going on.

Dipper stamped a hoof impatiently. Why was she so upset? Surely she knew he was just trying to help her! "I know, Mabel! But if it means you walking around on your own, isn't it worth it? Besides, according to Bill I'll need your help to find the stone! What other choice do we have?"

Swallowing, Mabel shook her head. "For all we know, he may not have been telling the truth! And who knows what he'll do with that stupid stone once he gets it? My dumb legs aren't important enough to risk giving that _demon_ what he wants," Mabel growled. She looked away as Dipper blinked, taken aback.

A torrent of hurt swirled in the pit of her stomach. Her words betrayed her usual cheerful character. Normally she'd be optimistic about such a situation, but this time was different. This time, _Bill_ was involved. She would never forget how Bill had tricked them not once but three times, each one worse than the last. The first time he'd almost stolen Grunkle Stan's memories, the second he tried to pit her against Dipper for their ideals, even stealing Dipper's body. And the third...her blind trust in Bill's disguise had nearly gotten them all killed. After the demon had shown up all those years ago, she remembered the growing rift that appeared between her and Dipper as their distinct personalities began to clash. Bill had drudged up the differences between them with his schemes, forcing the two to react in the ways true to their natures. It made their dissimilarities glaring and obvious, pulling them apart. The pointless arguments went on, keeping Mabel awake at night, sick with anxiety. Eventually, in the midst of despair, their sibling bond shone through the brutal predicament. They realized the issue and worked to repair what Bill had sundered, and had succeeded. But now the demon had appeared once again, and Mabel was terrified of what that meant for their relationship. She couldn't bear the thought of losing their tight bond again, which was why she pushed away her optimism automatically, apprehension hanging over her like a cloud. She gazed down into the water, her lips a thin white line, worry etched into her features.

Dipper's irritation with his sister vanished as he beheld her expression. She looked...frightened. She was terrified. Terrified of losing their bond as siblings, of the past repeating itself. A wave of anger washed over him as he remembered the demon's manipulation, the amount of grief he'd caused their family, and the fear that had scarred Mabel's heart. So sweet, loving and joyful she was, and Bill twisted it around to suit his desires.

Closing his eyes, Dipper took a calming breath. He gripped the edge of the tank with one hand and tipped Mabel's chin up with the other so she met his gaze. The anger replaced itself with determination. "Listen Mabel," he said seriously. "I know that making an agreement with Bill wasn't ideal, but now we've got a leg up. For now let's focus on finding both the cure and that mermaid thing. We can worry about Bill later. Okay? I know he's probably going to trick us but honestly, I don't care if it means I've got my one and only amazing sister with me every step of the way. With your help, there's not a doubt in my mind that we'll find that stupid cure." Taking a deep breath he added, "And nothing will come between us again. I promise."

Mabel's wide eyes softened, a smile creeping onto her face. At once she started giggling, surprising Dipper, and threw her arms around his shoulders. She squished him against the glass in a hug, unintentionally splashing water all over him. "Aww, thanks bro-bro! You know just how to cheer me up!"

Dipper extricated himself with a grunt, attempting to wipe off the droplets of water before returning her smile. "So...are the Mystery Twins back in action?"

Mabel laughed. "Of course we are!" She held out a fist, and he bumped it gently, grinning.

"All right," Mabel said excitedly. "When do we go looking for this mermaid jewelry thing? Right now?"

Dipper opened his mouth to speak only to be interrupted by Grunkle Stan barging into the room, tail knocking over a pile of magazines sitting on the floor. A broad grin was stretched across his granite face, yellow eyes glinting. In his hand he held a phone receiver, the cord stretched from the kitchen. "Kids, good news! The canals to the lake around the town limits are finished! The rest will be done in a couple days, or so they tell me. Oh, and dinner's ready..." He trailed off, gazing at the twins. "What's with you two? _You_ look like you just won that pig from the fair all over again," he said, pointing at Mabel's still beaming expression, "and _you_ look like that pig just peed on your shirt." He moved the point to Dipper, indicating his wet clothes.

Dipper began to give a retort before getting interrupted once again, this time by his mobile phone. Annoyed, he flipped it open. His eyes widened as he read the text, uttering a surprised exclamation. He looked up at the two confused faces before him. "Pacifica said she found something to do with Clinton Northwest!" he said, waving his phone at them. "I've gotta go meet her and see what it is," he said hurriedly, making his way to the door, almost tripping over his hooves with excitement.

"Hey, hey, hey," Grunkle Stan warned, closing the distance between them with a few quick strides. He grabbed Dipper by the shirt collar, dragging him back toward the kitchen, ignoring his protests. "Supper first, conspiracies later. Don't worry, even you can eat what I've got prepared with your wimpy vegetarian stomach," Stan assured him.

After retrieving Mabel from her tank, the three sat around the dinner table. While Stan and Mabel sat in their chairs normally, Dipper simply sat on the floor, back legs folded beneath him. He easily came up to about the same height as he would have had he been sitting in a chair as a human.

Dipper inhaled his food impatiently, eager to get going. He'd been waiting a week for this, and he _had_ to know what Pacifica found. Judging by her continuous text messages, it was more complicated than he initially thought.

Mabel studied her brother dejectedly. "Um, Dipper? Weren't we going to...y'know, check out the lake and stuff?"

Dipper finished his mouthful quickly before answering. "Sorry Mabel, can it wait till tomorrow? We've got a breakthrough here! Pacifica tells me she found something hidden in the mansion and that she needs my help. Once we get this sorted out I promise we'll go looking for your mermaid thing, okay?"

Mabel nodded. She understood, of course. She knew how frustrated he was with waiting for Pacifica to get back to him, and how desperately he wanted to continue the investigation. Now he finally could. It wouldn't take _too_ long, anyway. Waiting at home was fine with her, she supposed. She glanced down at her tail. Unless...

Once he was done eating, Dipper bolted upright, then bounded out of the kitchen and up the stairs. His rummaging around their room was easily heard from Mabel and Stan's spot at the table below.

Stan shook his head. "That kid, I swear," he grumbled. "Where does he get that energy?" He glanced at Mabel and sighed.

She was staring at the table forlornly. Her previous happiness had faded away, replaced with drooping eyes and a slightly turned-down mouth. He recognized that look all too well. The feeling of being left out was clear on her face. Both Stan and Mabel knew what Dipper was like, how he tended to get excited about his weird obsessions and often forgot about the people around him. His tunnel vision was remarkable in its own way, but sometimes harmful to others. This was one of those times. Stan cleared his throat, ready to right this wrong. Well, attempt to, anyway. Maybe his method wasn't one that a responsible parent would resort to, but thankfully he wasn't one of them.

"Look, sweetie," he said, startling Mabel. "I don't know exactly what's happening, but just because your brother has an adventure goin' on doesn't mean you can't have your own. We both know how he is, and it's not fair that you should be left out on the sidelines."

Mabel stared at him, hope creeping onto her face.

He continued, "howzabout I take you over to the canals, huh? Try them out for me, enjoy some time in the lake. As long as you don't get yourself into trouble, you hear? It's dangerous being out at night and I wouldn't allow it if I knew you couldn't handle it. Maybe get your friends together if they're available, put my mind at ease. Sound good?"

Mabel grinned, nodding happily.

Stan patted her shoulder affectionately. "Good. Now, let's get your stuff together. We'll leave once your brother's on his way. Make things less complicated than they need to be."

Dipper double checked his backpack, making sure he had everything he needed. By the time he'd arrived at the Northwest manor it was already dark, the stars winking into existence. Pacifica's text had been clear. Her parents' opinions be damned, it was time for them to do some investigating, and that meant sneaking around at night while most of the servants were asleep. From what she said, things could possibly get dangerous.

His supplies consisted of a flashlight, his journal and pen, a small first aid kit, a water bottle, candles and a lighter, and finally canisters of salt and iron filings. Okay, maybe the salt and iron was overkill, but Dipper knew what crazy things lurked in the mansion. He couldn't risk coming unprepared if a ghost got disturbed and decided to attack while they had their noses buried in old files.

Dipper waited at the gate, standing just behind the wall, out of sight. He poked his head out from his hiding place, gazing through the iron bars. The mansion stood quiet and regal before him, a few windows lit up with a soft yellow glow while the rest remained dark. The fountain burbled gently from its place in the middle of the courtyard, the driveway winding around it. The hedges spelling 'NW' were just as well-maintained as ever, and the freshly cut grass was a striking green.

How could anyone live in such a place? Dipper wondered, marveling. It was simply too fancy.

The skin on the nape of his neck began to crawl, and an uneasy feeling settled over him. He glanced around quickly, looking over his shoulder. For a brief moment it seemed as if a pair of glowing red eyes were staring out at him from the trees a short distance away. They vanished as soon as he looked, if they were even there to begin with. Dipper swallowed anxiously.

Suddenly, one of the gates inched open with a low creak, an arm poking through the bars and beckoning him inside. Dipper squeezed through the gap to meet Pacifica Northwest, still as equine as he remembered. She smiled as she greeted him, tucking her hair behind her long ears. Like Dipper, she wore a dark jacket and matching headband, not that they did much to camouflage her with her bright coloured hair. Her silver horn glinted in the moonlight. "Hey, glad you could make it." Her eyes flicked up to Dipper's newly-grown antlers. "Nice, um...antlers."

Dipper sighed. "Yeah, unfortunately they came with the whole cervitaur package."

Pacifica shook her head. "No it's fine, they...suit you. In a way. Anyhow," she said quickly as they began to walk. "We need to go around the side. I left the door unlocked and there are fewer servants that way. We'll have to sneak through the halls and get to the hidden room." They picked up the pace, hugging the property's boundary and sticking to the shadows.

"So what did you find in there?" Dipper asked as he sidestepped a wandering peacock. "It must be more than just information if you risked bringing me along."

Pacifica produced a sheaf of papers from her jacket. "Well, as it happens, there's more to the mansion than what the blueprints show."

"You mean a secret room?"

"Try a secret basement," she said, a smile on her lips. "At least, a part of the existing basement we didn't know about."

"What? How did you guys not know about it?"

Pacifica shrugged, tapping the folded papers. "I found these under some loose floorboards. My parents still don't have a clue about that room, by the way. From what I read it looks like Clinton bribed the construction workers into building it in secret. My great-great-great grandfather and his wife left town for some time during construction, and Clinton stayed behind. He must have had the builders do it while they were away."

"So this must've been when Clinton still had good relations with his family if they trusted him to oversee the construction on his own," Dipper reasoned. "But I still don't see why he'd go to the trouble of all this secrecy. Maybe he was getting annoyed with his brother for some reason, but this was before they had their falling out. They definitely had one at some point, going by that entry he wrote. But what caused it? Maybe he just didn't like sharing his treasure and had that secret area built to hide it." Dipper rubbed his forehead. "It looks like we both have crazy relatives with kleptomaniacal tendencies."

Pacifica giggled. "Looks like it. What you're saying makes sense, though. I'll show you this stuff once we get to the room." She hesitated, then added, "I can't stress this enough: we need to be quiet. I'll lead us through the halls where the servants don't spend as much time. Just follow my lead."

They skirted the perimeter of the courtyard and arrived at an area across from the side of the mansion. The two galloped across the lawn quickly, arriving at a small door set in the weathered oak, hidden by bushes. It seemed to be some kind of service hatch; inconspicuous and placed for the convenience of the staff.

Pacifica gripped the handle and looked up at Dipper. "Ready?"

Dipper took a deep breath. "Ready."

With that, the pair entered the mansion.

Mabel, meanwhile, had sent out a text of her own. With Dipper's map sealed safely in a Ziploc bag, she swam quietly through the canal, headed toward the lake. She couldn't simply sit twiddling her thumbs waiting for Dipper to return. She had her own treasure hunt to attend to! Boy would he be surprised when he next laid eyes on her. She giggled at the thought as she cut through the water gracefully, the moon shining down from its place in the serene night sky. The Mystery Twins were back in action, each pursuing their separate endeavours.


	10. Chapter 10

**Goodness, I'm so sorry this took so long. I went back and edited the conversation between Gideon and Dipper just a little bit so things make more sense, and I also edited the last chapter because I realize I screwed up the timeline pretty spectacularly. If you read the previous chapter anytime before Christmas you might want to go check it out. Up to you. Anyway, enjoy everyone, and happy holidays!**

 **Edit: Also thanks for everyone's kind comments, it really means a lot to me c: Also the anon who wished me well after I mentioned I had a cold, haha.**

* * *

The door shut behind them with a soft _click._

They were standing in a narrow corridor that kinked around a large room to their right. The hard oak floor echoed under their hooves, making Dipper wince at the noise. Tapestries hung from the walls and drapes obscured the windows. Mounted candles flickered, casting dancing shadows.

Dipper had seen the mansion at night only once before, at that grand party four years ago. Just thinking about the ghost with the huge axe and flaming beard was enough to make Dipper shiver, the echoing, hateful voice ringing in his ears. In the blanket of night the manor took on an entirely different feel. While no less grand, the hard oak felt older, the tapestries worn, and the halls ancient. During the day it felt empty for a mere family of three and its soulless servants to inhabit it, but at night it was a different story. The essence of lives long past were woven into the wood fibers, an echo of a different time pervaded throughout the halls. At night the mansion came alive with the sacrifices it was built upon, the records of treacheries it held.

In other words, it felt...haunted.

Glancing up and down the corridor, Pacifica unzipped her purse and reached inside. She produced a handful of cloth scraps, shoving them toward Dipper.

"Here, tie these around your hooves. Muffle the noise a bit," she whispered, already getting to work on her own.

Dipper nodded and kneeled down, doing as she asked. The cloth helped significantly to lessen the sharp _clack_ that resounded whenever one of them put a foot down and, satisfied, Pacifica beckoned Dipper to follow her.

They made their way down the hall quietly, looking around with wide eyes. Whenever they got to a corner where the corridor branched off, Pacifica would press herself flat against the wall and peek around it warily. Dipper followed her example, watching their backs. Once they had heard footsteps headed their way from around a corner ahead of them and the two had backed up in alarm, shrinking into the shadows. Thankfully the servant had turned the corner away from them, entering a room without looking their way. Pacifica, letting out a shaky breath, once again took the lead.

Soon they reached the back doors that led out from the heart of the mansion and into the enclosed garden. The grand doors were overgrown with ivy from the outside, and inside were flanked by potted plants. Across from the door behind them was one of the grand rooms the hallway had wound around. A large arch was the only thing standing between it and the door to the garden, leaving them exposed if they wanted to go outside. Peeking into the large open room, Pacifica made sure it was devoid of people before slipping outside, Dipper close behind.

They made their way across the stretch of green, surrounded by hedges and peacocks. The cool night air was a welcome relief from the stuffy interior. Dipper glanced around, taking in the decorative area. It looked just the same as it had when he and Pacifica were running through it for their lives, desperately looking for a way to escape the lumberjack spirit.

Soon they entered the corridor with the secret room, pushing through the ruined painting and slipping inside. Dust billowed around them in the sudden motion. The room was much colder than the rest of the manor, and any furniture was covered in white sheets, a thick layer of dust blanketing them. Stacks of books and boxes littered the floor, evidence of Dipper and Pacifica's investigating. The old, faded paintings still leaned against one wall, tall floor mirrors haphazardly strewn around them. The room was dark, but enough light seeped in from the hall that neither needed to use their flashlight. Musty air choked the room, cobwebs decorated the walls and ceiling.

Pacifica let out a pent-up breath, her tail flicking nervously. She seemed very apprehensive about this act of rebellion, which made Dipper wonder just how much worse her father's mood had gotten as a result of the curse.

She reached into her jacket and brought out the thin stack of papers she'd shown him earlier. Rifling through it, she selected one and held it out to Dipper. "I found this one under the floorboards here," she said, moving to a spot in the far left corner of the room. "Go ahead and take a look while I see if there's anything else here."

The piece of paper was old and worn, but matched the scrap of journal paper he'd read earlier by the lake. While Dipper pored over its contents, Pacifica checked for any other loose floorboards.

The journal entry told of the time Clinton was left to his own devices while the manor was being built, written in an excitable, flowing hand:

'Excellent! With my brother and his irksome wife out of the way, I now have full run of the construction. The builders have dropped everything to build the secret basement and cover it up before they return, just as I asked. The secret passage from the basement to my room is also under construction, complete with a lock mechanism that only I know the code to. Perfect...with this I'll never have to share my treasure again. Not only that, but _he_ will be pleased to see...' regrettably, the rest had been charred black and ruined.

Dipper threw his hands into the air. "What's with vital information being ruined all the time?! Is it too much to ask for _one_ little thing to go right for once?" He exclaimed, proceeding to mutter angrily under his breath. He looked up at Pacifica. She'd taken to staring at him with a slightly amused expression. Dipper felt his face go red. There he went, getting carried away again. Coughing awkwardly, he made his way over to where she was standing. "So, find anything?"

"I have, actually, but I need your help. I was about to call you over before you had your little, um, episode." She gestured to a section of the wall.

It looked just like the rest of the room, with the wooden boards curling slightly out of old age and bleached of colour. When Dipper looked closer, he noticed little hinges with flaking paint protruding from between two boards. A few panels to the right he saw a strip of metal running down to the floor, wedged into the wood and covered in the same peeling paint. He followed it down to where it veered off to the right, only for the rest to be obscured by an enormous dresser.

"Ah."

Pacifica rounded the dresser and gripped the other end. "You push, I'll pull."

Dipper nodded and braced himself against it, counting to three before giving a mighty heave. With a groan, it moved grudgingly. All seemed to be going well until, for the last couple inches, it produced an ungodly shriek as its feet ground against the uneven floor. Halting at once, Dipper flattened his ears, cringing. Pacifica did likewise, paling considerably.

"Shoot," she muttered. "Hopefully no one heard that."

Dipper glanced behind him and saw that the rest of the metal strip had been uncovered, so he beckoned Pacifica over.

The strip led to a long rectangular plate of metal nailed into the wood. Set in the middle was a row of eight rotating wheels, similar to a number lock, but with ten random letters stamped into each face rather than numbers.

Dipper scratched his head and folded his legs beneath him as he bent to take a closer look. The letters of each wheel were completely random, with no regard to alphabetical order whatsoever.

"Fantastic," Dipper muttered. "How are we gonna get the code?" He glanced at Pacifica.

She shrugged. "Don't look at me! You're supposed to be the smart one."

"What, nothing in those documents said anything about a password?" He asked, raising an eyebrow.

She sighed, shifting her stance impatiently. "Most of them were from before the manor was built. I never saw anything about a code or even about the secret room except for that page there," she said, pointing at the scrap of paper still clutched in Dipper's hand.

He scanned over the page again, looking for any clues he might have missed. He began to enter a few different possibilities, only to halt when the wheels lacked the right letters. After a few guesses he leaned back, ruffling a hand through his hair, bumping his fingers into antlers.

"Nothing." Uttering a curse, he stared at the evil thing angrily. They were so close! How could they be stopped by a stupid lock set up by a treasure hunting weirdo?

A thought occurred to him. "I don't suppose the door was left unlocked?" He asked hopefully.

Pacifica walked over to the door, wedging her fingers between the boards and pulling. "Nope. We're on our own here."

Dipper sighed. "Figures." Taking a deep breath, he closed his eyes.

 _Think_. He wracked his brain, drawing up information he knew about Clinton and discarding anything he deemed unimportant. Eight letters. The man clearly didn't get along very well with his family, so that ruled out anything to do with them. He was very independent and didn't seem to have had a significant other, at least not one that he'd mentioned in his entries. The life of a rogue treasure hunter was very exciting, and no doubt he'd loved every moment of it. Heck, he'd even disappear for years at a time on journeys, and the excitement shown in his record of stolen items indicated just how memorable each one was. So, something to do with his past work? Possibly. Problem was, Dipper knew very few of these journeys, having only read a couple of the ones Pacifica had given him. Biting his lip, he berated himself for not delving deeper and reading the other entries. He turned over fact after fact in his mind, frustrated with the precious little he knew about the man.

Just as he was about to give up, something clicked. Eight letters. A past journey. Presumably a memorable experience, going by the blurb he wrote. The nail-biting excitement that had seeped into the paper as the words flowed from the fountain pen. Something that had seemed odd and unimportant at the time now seemed the best candidate for the job.

Dipper opened his eyes and, with shaking fingers, input the code.

B-E-A-T-R-I-C-E.

Beatrice the savage barmaid from Transylvania.

There was a whirring sound and several clicks as bits of metal fell into place behind the wood. Dipper rose to his hooves and stood by Pacifica as she stared at the door in amazement. It swung open, revealing a narrow stone passageway that descended into complete darkness.

She glanced at Dipper in awe. "How did you figure it out?"

Dipper shrugged, a half smile on his face. "I'm the smart one, remember?"

Pacifica smirked, then gestured at the passageway. "After you."

Dipper switched on his flashlight and the two descended into darkness, unaware of the glinting red eyes that watched from the shadows.

Mabel squinted up at the moon. It gazed back at her silently. She was floating in the lake, waiting by the entrance of the canal. She'd told Candy and Grenda to meet her there but they had yet to show. A cool breeze brushed the water's surface, creating tiny ripples that distorted the moon's reflection. The stars winked down at her from their positions in the inky black sky, wisps of cloud floating gently. Mabel shivered and sank further into the water, up to her chin. She glanced around nervously. The trees surrounding the lake were dark and uninviting, giving the impression that any sort of unspeakable horror could be lurking within them.

A little _splish_ sound drew her attention back to the canal. She watched the tunnel expectantly, picking up a ripple coming from its depths. When nothing showed she frowned, dunking her head underwater to get a different perspective. She came nose to nose with a grinning, scaly green face. Shrieking, Mabel flew backward, splashing in terror. Grenda burst out of the water, laughing and slapping the surface with glee. Candy materialized behind her, black-rimmed eyes blinking.

Mabel let out a breath, shock melting into annoyance then quickly to happiness. "Grenda! You scared me!" She said, splashing her.

Grenda continued giggling, hugging her stomach, evidently in a happy sort of pain. "I know! That was the whole point! I'll never forget the look on your face!" She doubled over laughing once again, submerging her head so that only bubbles indicated her mirth.

Candy adjusted her water-speckled glasses. "It's moments like these that make me wish I had taken a photo...one that I may have used as blackmail." She smiled sweetly at her.

Mabel giggled. "Oh, cut it out you two," she said as Grenda finally resurfaced, breathing heavily with a toothy grin on her face.

"So what did you call us here for, Mabel?" Candy asked.

"Yeah, we were about to play an intense game of knuckles!" Grenda said, clenching her fist.

Candy gulped, looking at Mabel with wide eyes. Clearly she was glad to have gotten away from that.

Mabel grinned. "Oh, you girls won't _believe_ this! So, Dipper found out about this _amazing_ thing..." She proceeded to fill them in on the details of the mermaid bracelet and showed them Dipper's 'expertly drawn' map. She pointed to the spot that indicated the underwater cave, explaining that the treasure was hidden within it.

"There's just one problem," Mabel said, energy fading slightly. "When we were swimming here a week ago, I saw this monster kind of...thing. At the bottom of the lake, near where we need to go. It was green, and scaly, and terrifying." She shivered.

Grenda and Candy were quiet for a moment. Then Grenda started chuckling unexpectedly. "Gee, sorry Mabel, I didn't mean to scare you so much."

Mabel sighed, exasperated. "No, Grenda, I didn't mean you! You're one of my besties, I'd never mistake you for a monster. No, I saw it near Scuttlebutt Island, right by the waterfall. Problem is, the cave is right around there too."

Candy adjusted her glasses, frowning. "Can't we just rent a boat to get there?"

Mabel glanced over her shoulder at the rental joint. "Not since the owner was transformed into a bottom feeder and disappeared into the lake, I'm afraid."

The tiny hut was empty and desolate, the sign hanging from a single nail, swinging in the gentle breeze with shrill little creaks. Even if they wanted to 'borrow' a boat without permission, they wouldn't be able to get it up and running by themselves. Besides, she remembered with a shudder, the boat they'd used last time did little to withstand the onslaught of a furious sea monster.

She turned back toward them, a determined expression graced her face. "Don't worry girls, I've got a plan."

The plan was simple. Well, what Mabel considered a plan was really a hare-brained and slightly delusional scheme that also happened to be morbidly dangerous. Thankfully Grenda and Candy, being the extraordinarily supportive friends they were, went through with it anyway. It was classic, the beauty of its straightforwardness making it incredibly easy to follow and requiring very little explanation. Once the three had gone over it a couple times, they got to work. While boats were currently out of the question, easing their way into the hut and grabbing heaps of bait, on the other hand, was not.

They swam quietly, drifting through the still waters with hardly a ripple. Mabel tugged along a cooler behind her, its buoyancy weighed down by the contents.

As they swam further and further into the lake, a white fog began to creep up on them, drifting across the water's surface. The scene looked like something out of a horror movie: a still lake with a full moon shining down; a foggy night with dark spruce trees cutting a jagged line against the night sky, encircling the water's edge. Knowing Gravity Falls anything could have been lurking in the forest, from werewolves to fairies, and those stories became much easier to believe on a night like this. It was outright creepy and Mabel, as brave as she was, probably would have turned tail and ran (swam?) if it weren't for her two friends pressing close on either side.

Soon Scuttlebutt Island rose from the fog before them, looming and pitch dark. Its craggy shores were cold and uninviting, but thankfully they had no need to go there.

Once Mabel was sure they'd gotten close enough, she halted, gesturing for her friends to do the same. She dunked her head under the water, peering through the clear depths. Sure enough, there was the monster, circling the island in some kind of patrol. Its beady green eyes glowed through the darkness, its massive bulk casting rolling waves through the water that stirred the silt and flattened the plants.

She gulped, surfacing. They couldn't afford to mess up. This whole idea was absolutely ludicrous, but she was sick of being useless, of being confined to a tank. She had to show everyone (and more importantly, herself) that she _could_ accomplish something in her condition, even if it was as challenging and dangerous as this. For her efforts she would be awarded something that would allow her to do even _more_ \- for the town, for Grunkle Stan, and most of all, for Dipper. Mabel needed this item, and she needed her mobility. Not just for herself but for everyone she could help with it. She wouldn't allow herself to feel useless again.

Mabel returned her attention to the matter at hand, facing her friends. "All right, girls," she whispered, beckoning them closer. "This is the place. Remember the plan: you guys get ready to swim past and I'll distract 'em with this." She gestured to the cooler of chum. As the fastest swimmer of the three, she would be the one to open the cooler and push it towards the monster, then swim away quickly before it finished its meal. The three would round the island and make it to the cave, hopefully with all limbs still attached.

The two nodded, faces set in determination. They swam off to the side, waiting for the signal.

Mabel took a deep breath. This was insane. Absolutely, thoroughly nuts. But, she thought giddily, _very_ exciting.

As the monster once again rounded the island, heading her way, she pushed the cooler toward it. It bobbed along gently, its course set to intercept the monster's path. It was time to set the plan in motion.

* * *

 **Grr I wanted to get so much more done in this chapter but it just got too long. The next one will be pretty action-packed, I can assure you. Thanks for reading :)**


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